B is right answer ithink bro/sis
Answer:
A and B
Explanation:
The activation energy is the minimum energy necessary for the reaction to happen. It is a barrier, the reaction only occurs if the reactants have that energy.
As higher is the activation energy, as difficult is to the reaction happens, and because of that, the reaction rate will be small. The rate indicates the reaction velocity, which is the velocity of the collisions of the molecules, with more collisions, higher randomness is presented, and higher is the velocity.
A) Correct. As less energy is necessary, as higher is the velocity of the reaction, so the randomness and the rate will increase.
B) Correct. Is the definition of activation energy.
C) Incorrect. They indicate the rate of the reaction, and how easy or not it will be to the reaction happen.
D) Incorrect. As higher is the activation energy, as low is the randomness and the rate of the reaction.
If 10.0 L of oxygen gas at STP are heated to 512 Celsius what will be the new volume of the gas if the pressure is also increased to 1.75 ATM?
Answer:
16.4 L
Explanation:
we can use the combined gas law equation that gives the relationship among volume, temperature and pressure conditions of gases.
P1V1/T1 = P2V2/T2
STP conditions are standard temperature and pressure conditions
P1 is standard pressure = 1 atm , T1 is standard temperature = 273 K
and V1 is the volume
P2 is pressure, T2 is temperature and V2 is volume at the second instance
temperature is in kelvin scale,
512 ° + 273 = 785 K
substituting the values in the equation
1 atm x 10.0 L / 273 K = 1.75 atm x V / 785 K
V = 16.4 L
new volume is 16.4 L
What is the value of n in CH3(CH2)nCH3 if the name of the hydrocarbon is heptane
Answer:
n = 5.
Explanation:
How many carbon atoms in total in this straight-chain hydrocarbon?
The prefix of the IUPAC name of a hydrocarbon (the part before -ane) shows the number of carbon atoms on the longest carbon chain.
[tex]\begin{array}{c|c}\text{Number of Carbon}\\ \text{atoms in backbone} & \text{Prefix}\\[-0.5em]\multicolumn{2}{c}{\rule{5cm}{0.5pt}}\\1& \text{meth-} \\ 2&\text{eth-} \\ 3&\text{prop-}\\4 & \text{but-}\\5 & \text{pent-} \\ 6 & \text{hex-} \\ 7 & \text{hept-} \\8 & \text{oct-}\\ \dots & \dots\end{array}[/tex].
Name of this hydrocarbon: heptane;Prefix: hept-;Number of carbon atoms in the longest chain: 7.Hence the structure:
[tex]\text{CH}_3\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-CH}_2\text{-CH}_3[/tex].
All the [tex]\text{-CH}_2\text{-}[/tex] in the formula might look redundant. "[tex]\text{CH}_2[/tex]" appears five times in a row and may be condensed into [tex](\text{CH}_2)_5[/tex]. Hence the condensed formula:
[tex]\text{CH}_3\text{-}{(\text{CH}_2)_{\bf5}\text{-CH}_3[/tex].
Therefore [tex]n = 5[/tex].
Answer:
n+5 so the correct answer is b) 5
Explanation:
just did review on edge
Type the correct coefficients for the following reaction: Al+S2 - > Al2S3
Answer:
2(Al 3+) + 3/2 O2 ---> Al2O3
Answer:
The correct coefficients for the following reaction:
[tex]4Al+3S2\rightarrow 2Al_2S_3[/tex]
Explanation:
[tex]Al+S2\rightarrow Al_2S_3[/tex]
Given reaction is not balanced.
According to Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
This also means that total mass on the reactant side must be equal to the total mass on the product side.
Stoichiometric coefficient is the numeral written before the chemical compound in a balance chemical reaction.
[tex]4Al+3S2\rightarrow 2Al_2S_3[/tex]
Look at the graph below. Will mark brainliest
A graph is shown with Absolute Brightness shown on y axis and Surface temperature in degree Celsius shown on x axis. The Dwarf stars are shown along a slanting line from coordinates 30,000 and minus 3 to 10,000 and minus 4. The Main Sequence stars are shown along a slanting line from coordinates 20,000 and minus 2 to 2,000 and minus 6. The giants are shown along a line parallel to the x axis from coordinates 5,000 and 2 to 2,000 and 3. The supergiants are shown along a line parallel to the x axis from coordinates 7,500 and 4 to 2,500 and 4. Point A has coordinates 20,000 and minus 4. Point B has coordinates 2,500 and minus 4. Point C has coordinates 5,000 and 2. Point D has coordinates 7,000 and 4.
Which of the following stars is most likely to be blue?
Star A
Star B
Star C
Star D
Answer:
Star A
Explanation:
Based on the information provided, we can determine that the color of a star is related to its surface temperature, with hotter stars appearing more blue and cooler stars appearing more red.
Looking at the graph, we can see that the stars along the left side of the graph (with negative values on the x-axis) are hotter than the stars on the right side of the graph. Therefore, Star A, which has coordinates of 20,000 and -4, is hotter than Star B, which has coordinates of 2,500 and -4.
Comparing the coordinates of Star A to the lines representing the different types of stars, we can see that it falls on the line for main sequence stars. Main sequence stars are typically white or blue-white in color, so Star A is most likely to be blue.
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Star D is most likely to be blue, as it has a high surface temperature compared to the other stars listed (7,000 degrees Celsius) and aligns with the typical characteristics of blue stars.
The color of a star is closely related to its surface temperature. Hotter stars tend to appear bluer, while cooler stars appear redder.
Looking at the provided coordinates for the stars:
- Star A has coordinates (20,000, -4), indicating a high surface temperature.
- Star B has coordinates (2,500, -4), indicating a lower surface temperature.
- Star C has coordinates (5,000, 2), indicating a moderate surface temperature.
- Star D has coordinates (7,000, 4), indicating a relatively high surface temperature.
Among the given stars, Star A and Star D have the highest surface temperatures, making them more likely to appear blue. However, between these two, Star D has an even higher temperature, making it the most likely to be blue. Therefore, Star D is the star most likely to be blue.
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What is the number of moles in 500 L of He gas at STP
Answer:
22.3 mol
Explanation:
He is in STP conditions
This means that it is in standard conditions of temperature and pressure, under these conditions the pressure has a value of 1 atm and the temperature has a value of 273 K
To calculate the number of moles in 500L of He gas we use the ideal gas equation
[tex]P.V=n.r.T\\r(constant of ideal gases)= 0.082\frac{atm.L}{K.mol}[/tex]
We cleared the moles (n)
[tex]P.V=nr.T\\\frac{P.V}{r.T}=n\\\frac{1atm.500L}{0.082atm.L/K.mol.273K}=n\\\\22.3 mol=n[/tex]
The number of moles in 500 L of He gas at STP 22.3 mol
The number of moles in 500 L of helium (He) gas at standard temperature and pressure (STP) is approximately 22.32, based on the standard molar volume concept of chemistry.
Explanation:The number of moles in 500 L of He gas at STP can be determined using the standard molar volume, which states that at standard temperature and pressure (STP), one mole of any ideal gas occupies a volume of 22.4 L. In this case, to find the moles of helium gas, you would use the formula n = V/V_m, where n is the number of moles, V is the volume of the gas, and V_m is the molar volume at STP.
Substituting the given values into the equation: n = 500 L/22.4 L/mol = 22.32 moles.So, there are approximately 22.32 moles of helium gas in 500 L at STP.
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Describe the difference between chemical and physical weathering
Difference Between Chemical and Physical Weathering.
Weathering processes crack, wear away, and weaken rocks.
While physical weathering breaks down a rock's physical structure, chemical weathering alters a rock's chemical composition.
Final answer:
Physical weathering is the process of breaking down rocks without changing their chemical composition, while chemical weathering involves chemical reactions that alter the composition of rocks. Physical weathering can occur through forces like freeze-thaw cycles, while chemical weathering can happen through processes like oxidation and hydration.
Explanation:
Physical weathering, also known as mechanical weathering, is the process of breaking down rocks and minerals into smaller pieces without changing their chemical composition. This occurs through physical forces such as freeze-thaw cycles, temperature changes, abrasion, and pressure.
Chemical weathering is the process in which rocks and minerals are broken down by chemical reactions that alter their composition. This can happen through processes such as oxidation, hydration, hydrolysis, and carbonation. Chemical weathering can result in the formation of new minerals and alteration of the rock's structure.
An example of physical weathering is when water freezes in cracks in a rock, causing it to expand and eventually crack. An example of chemical weathering is the reaction between water and limestone, which leads to the formation of caves and sinkholes.
A compound has the percent composition 47.40% Pd, 28.50% O, 21.40% C, and 2.69% H. Based on this information, which molecular formulas could represent the compound?
PdO2C2H3
Pd(O2CCH3)2
Pd(O2C2H3)3
PdO4C2H9
Pd2C8H12O8
Answer:
Pd(O₂CCH₃)₂
Explanation
Answer:
Pd(O2CCH3)2
Pd2C8H12O8
Explanation:
Given:
% Pd = 47.40
% O = 28.50
% C = 21.40
% H = 2.69
To determine:
Molecular formula of the compound containing Pd, O, C and H
Calculation:
Let the mass of the compound = 100g
Therefore based on the % compositions:
Mass of Pd = 47.40g
Mass of O = 28.50g
Mass of C = 21.40g
Mass of H = 2.69g
Atomic mass of Pd = 106.42 g/mol
Atomic mass of O = 15.99 g/mol
Atomic mass of C = 12.01 g/mol
Atomic mass of H = 1.00 g/mol
[tex]moles\ of\ Pd = \frac{47.40g}{106.42g/mol} =0.4454[/tex]
[tex]moles\ of\ O = \frac{28.50g}{15.99g/mol} =1.782[/tex]
[tex]moles\ of\ C = \frac{21.40g}{12.01g/mol} =1.782[/tex]
[tex]moles\ of\ H= \frac{2.69g}{1.00g/mol} =2.690[/tex]
Ratio:
[tex]Pd = \frac{0.4454}{0.4454} = 1.00\\\\O = \frac{1.782}{0.4454} = 4.00\\\\C = \frac{1.782}{0.4454} = 4.00\\\\H = \frac{2.690}{0.4454} = 6.039[/tex]
The empirical formula is : PdO4C4H6
Molecular formula = n(Empirical formula)
If n = 1
Molecular formula = PdO4C4H6 i.e. Pd(O2CCH3)2
If n= 2
Molecular formula = 2(PdO4C4H6)= Pd2O8C8H12
Which best describes why a liquid needs a container when a solid does not?
liquid is fluid in motion, needing to be contained. while a solid state of matter is as such and won't run down the cabinet
Answer:
When an element or substance is in a liquid state, the particles are joined by less attractive forces than in solids, for this reason the particles of a liquid can move freely.For this reason the particles of a liquid can move freely and need a recipient that contains them .
Liquids have a defined volume but with a variable shape, this means that liquids adopt the shape of the container but always occupy the same space
For example, if we have 4 L of water in a round container, its shape is round and now we put the water in a square container, its shape is now square but its volume is still 4 L (it continues to occupy the same space)
Excess magnesium reacts with 165.0 grams of hydrochloric acid in a single displacement reaction.
What volume of hydrogen gas is produced at STP?
Answer:
The volume of hydrogen gas produced will be approximately 50.7 liters under STP.
Explanation:
Relative atomic mass data from a modern periodic table:
H: 1.008;Cl: 35.45.Magnesium is a reactive metal. It reacts with hydrochloric acid to produce
Hydrogen gas [tex]\rm H_2[/tex], andMagnesium chloride, which is a salt.The chemical equation will be something like
[tex]\rm ?\;Mg\;(s) + ?\;HCl \;(aq)\to ?\;H_2 \;(g)+ [\text{Formula of the Salt}][/tex],
where the coefficients and the formula of the salt are to be found.
To determine the number of moles of [tex]\rm H_2[/tex] that will be produced, first find the formula of the salt, magnesium chloride.
Magnesium is a group 2 metal. The oxidation state of magnesium in compounds tends to be +2.
On the other hand, the charge on each chloride ion is -1. Each magnesium ion needs to pair up with two chloride ions for the charge to balance in the salt, magnesium chloride. The formula for the salt will be [tex]\rm MgCl_2[/tex].
[tex]\rm ?\;Mg\;(s) + ?\;HCl\;(aq) \to ?\;H_2 \;(g)+ ?\;MgCl_2\;(aq)[/tex].
Balance the equation. [tex]\rm MgCl_2[/tex] contains the largest number of atoms among all species in this reaction. Start by setting its coefficient to 1.
[tex]\rm ?\;Mg\;(s) + ?\;HCl\;(aq) \to ?\;H_2 \;(g)+ {\bf 1\;MgCl_2}\;(aq)[/tex].
The number of [tex]\rm Mg[/tex] and [tex]\rm Cl[/tex] atoms shall be the same on both sides. Therefore
[tex]\rm {\bf 1\;Mg}\;(s) + {\bf 2\;HCl}\;(aq) \to ?\;H_2 \;(g)+ {1\;\underset{\wedge}{Mg}\underset{\wedge}{Cl_2}}\;(aq)[/tex].
The number of [tex]\rm H[/tex] atoms shall also conserve. Hence the equation:
[tex]\rm {1\;Mg}\;(s) + {2\;\underset{\wedge}{H}Cl}\;(aq) \to {\bf 1\;H_2 \;(g)}+ {1\;MgCl_2}\;(aq)[/tex].
How many moles of HCl are available?
[tex]M(\rm HCl) = 1.008 + 35.45 = 36.458\;g\cdot mol^{-1}[/tex].
[tex]\displaystyle n({\rm HCl}) = \frac{m(\text{HCl})}{M(\text{HCl})} = \rm \frac{165.0\;g}{36.458\;g\cdot mol^{-1}} = 4.52576\;mol[/tex].
How many moles of Hydrogen gas will be produced?
Refer to the balanced chemical equation, the coefficient in front of [tex]\rm HCl[/tex] is 2 while the coefficient in front of [tex]\rm H_2[/tex] is 1. In other words, it will take two moles of [tex]\rm HCl[/tex] to produce one mole of [tex]\rm H_2[/tex]. [tex]\rm 4.52576\;mol[/tex] of [tex]\rm HCl[/tex] will produce only one half as much [tex]\rm H_2[/tex].
Alternatively, consider the ratio between the coefficient in front of [tex]\rm H_2[/tex] and [tex]\rm HCl[/tex] is:
[tex]\displaystyle \frac{n(\text{H}_2)}{n(\text{HCl})} = \frac{1}{2}[/tex].
[tex]\displaystyle n(\text{H}_2) = n(\text{HCl})\cdot \frac{n(\text{H}_2)}{n(\text{HCl})} = \frac{1}{2}\;n(\text{HCl}) = \rm \frac{1}{2}\times 4.52576\;mol = 2.26288\;mol[/tex].
What will be the volume of that many hydrogen gas?
One mole of an ideal gas occupies a volume of 22.4 liters under STP (where the pressure is 1 atm.) On certain textbook where STP is defined as [tex]\rm 1.00\times 10^{5}\;Pa[/tex], that volume will be 22.7 liters.
[tex]V(\text{H}_2) = \rm 2.26288\;mol\times 22.4\;L\cdot mol^{-1} = 50.69\; L[/tex], or
[tex]V(\text{H}_2) = \rm 2.26288\;mol\times 22.7\;L\cdot mol^{-1} = 51.37\; L[/tex].
The value "165.0 grams" from the question comes with four significant figures. Keep more significant figures than that in calculations. Round the final result to four significant figures.
Sharing electrons between atoms indicates an ionic bond.
A. True
B. False
The sharing electrons between atoms indicates an ionic bond is FALSE.
I hope this helps
The sharing of electrons between atoms indicates an ionic bond is option B. False.
Why does the sharing of electrons between atoms indicate an ionic bond is False?Ionic bonding is presented as the complete transfer of valence electrons, typically from a metal to a non-metal.In reality, electron density remains shared between the constituent atoms, meaning all bonds have some covalent character.The ionic or covalent nature of a bond is determined by the relative electronegativities of the atoms involved.The bond that involves the sharing of electron pairs between atoms is that what kind of atoms form covalent bonds with nonmetals why do metals not form covalent bonds they don't hold onto their electrons well.Hence, the sharing of electrons between atoms indicates an ionic bond is False.
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(Show your work please)
Answer:
[tex]\boxed{\text{bp =100.106 }^{\circ}\text{C; fp = -0.387 }^{\circ}\text{C; bp =101.68 }^{\circ}\text{C}}[/tex]
Explanation:
Q8. Boiling point
Data:
m(KOH) = 53.1 g
m(H₂O) = 9.10 kg
K_b = 0.512 °C·kg·mol⁻¹
Calculations:
(a) Moles of KOH
[tex]\text{Moles of KOH} = \text{53.1 g KOH} \times \dfrac{\text{1 mol KOH}}{\text{56.11 g KOH}} = \text{0.9464 mol KOH}[/tex]
(b) Molal concentration
The formula for molal concentration (b) is
[tex]b = \dfrac{\text{moles of solute}}{\text{kilograms of solvent}} = \dfrac{0.9464}{9.1} = \text{0.104 mol/kg}[/tex]
(c) Boiling point elevation
The formula for the boiling point elevation ΔTb is
[tex]\Delta T_{b} = iK_{b}b[/tex]
i is the van’t Hoff factor: the number of moles of particles you get from a solute.
For KOH,
KOH(s) ⟶ K⁺(aq) + OH⁻(aq)
1 mol KOH ⟶ 2 mol particles i = 1
[tex]\Delta T_{b} = 2 \times 0.512 \times 0.104 = \text{0.106 }^{\circ}\text{C}[/tex]
(d) Boiling point
[tex]T_{b} = T_{b}^{\circ} + \Delta T_{b} = 100.000 + 0.106 = \text{100.106 }^{\circ}\text{C}[/tex]
Q9. Freezing point
[tex]\Delta T_{f} = iK_{f}b = 2 \times 1.86 \times 0.104 = \text{0.387 }^{\circ}\text{C}\\\\T_{f} = T_{f}^{\circ} - \Delta T_{f} = 0.000 - 0.387 = \text{-0.387 }^{\circ}\text{C}[/tex]
Q10. Boiling point
[tex]\text{Kilograms of phenol} = 645 \times \dfrac{1}{1000} = \text{0.645 kg phenol}\\\\b = \dfrac{0.910}{0.645} = \text{1.411 mol/kg}\\\\\Delta T_{b} = 1\times 1.19 \times 1.411 = \text{1.68 }^{\circ}\text{C}\\T_{b} = 100.00 + 1.68 = \text{101.68 }^{\circ}\text{C}[/tex]
At 98.66 kPa and 20 degrees C nitrogen has a solubility in water of .018 g/L. At 82.66 kPa and 20 degrees C, it’s solubility is .015 g/L. Does nitrogen obey the gas pressure-solubility law?
Yes it’s corrrct I swear
At 98.66 kPa and 20°C nitrogen has a solubility in water of .018 g/L. At 82.66 kPa and 20°C, it’s solubility is 015 g/L. Nitrogen obey the gas pressure solubility law.
What is Henry Law ?Henry's Law is a gas law states that the solubility of a gas in liquid is directly proportional to the pressure of that gas.
It is expressed as:
[tex]P_{i} = K_{H}\ X_{i}[/tex]
where,
[tex]P_{i}[/tex] = Partial pressure of the gas
[tex]X_{i}[/tex] = Mole fraction of gas
[tex]K_{H}[/tex] = Henry's Law constant
Which will not obey Henry Law ?Ammonia, Hydrogen halide (like Hydrochloric acid) and Hydrogen sulfide these gases does not obey Henry's Law.
Thus from the above conclusion we can say that At 98.66 kPa and 20°C nitrogen has a solubility in water of .018 g/L. At 82.66 kPa and 20°C, it’s solubility is 015 g/L. Nitrogen obey the gas pressure solubility law.
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How to find the valency of an element. 100 points and brainleiest for first answer. Plus thanks. Also how to ace chemistry exams that are tomorrow.
vertical colums tell the valence and the horozontal rows tell the amount of rings that the electrons circle in.
It is easy to find this by simply looking at the Group # (these are the column numbers).
Elements in Group 1 all have 1 electron in their valence shell, Elements in group 2 have 2 and so on...
If you mean how many shells there are then look at the Period # this is the horizontal groups) the Period # corresponds with the number of electron shells.
Elements in Period 2 have 2 electron shells, elements in Period 3 have 3 and so on...
To determine the valency of an element, one must consider its position in the periodic table and its electron configuration.
The valency of an element is the number of electrons it can lose, gain, or share when forming chemical compounds.
1. Main Group Elements (Groups IA to VIIIA, except He):
- Groups IA and IIA: The group number gives the valency. For example, elements in Group IA (e.g., Na) have a valency of 1, and those in Group IIA (e.g., Mg) have a valency of 2.
- Groups IIIA to VIA: The valency can be determined by subtracting the group number from the total number of valence electrons (8 for nonmetals, 18 for noble gases). For example, Nitrogen (Group VA) has 5 valence electrons, so its valency is 8 - 5 = 3.
- Halogens (Group VIIA): These elements have 7 valence electrons, so they have a valency of 1 (since they tend to gain one electron to achieve a full valence shell).
- Noble Gases (Group VIIIA): These elements typically have a valency of 0 because they have a full valence shell.
2. Transition Metals (Groups IB to VIIIB):
- These elements can exhibit multiple valencies, often corresponding to different oxidation states. Commonly, the valency is one or two less than the group number. For example, Iron (Fe, Group VIIIB) can have valencies of 2 or 3.
3. Inner Transition Metals (Lanthanides and Actinides):
- These elements also exhibit multiple valencies, usually +3 or +4.
4. Metalloids (B, Si, Ge, As, Sb, Te):
- Their valency can vary depending on the compound they form. For example, Silicon (Si) can have valencies of 4 or -4.
To ace chemistry exams, consider the following strategies:
- Understand Concepts: Ensure you have a solid grasp of the fundamental concepts rather than just memorizing facts.
- Practice Problems: Work through a variety of problems, especially those from past exams if available.
- Study Regularly: Spread out your study sessions over time rather than cramming the night before.
- Organize Study Material: Use flashcards, charts, and diagrams to help visualize and remember information.
- Form Study Groups: Discussing concepts with peers can provide new insights and clarify misunderstandings.
- Ask for Help: If you're struggling with certain topics, don't hesitate to ask teachers or tutors for clarification.
- Stay Healthy: Get enough sleep, eat well, and stay hydrated to ensure your brain is functioning optimally.
- Manage Time During the Exam: Allocate your time wisely, answering easier questions first and returning to more challenging ones later.
By applying these strategies and understanding the principles behind chemical reactions and the periodic table, you can improve your performance in chemistry exams.
What is calcium used for in our body?
Answer:
It is necessary for contracting muscles, forming and strengthening bones and teeth, conducting nerve impulses throughout the body, clotting blood, maintaining a normal heartbeat
Answer:
calcium is essential for living organisms. it is vital for the body's good health.
Bone health
Vitamin D is helps the body absorb and retain calcium
it helps with muscle contraction
helps in normal blood coagulation (clotting)
it is a co-factor for many enzymes
helps the smooth muscles that surrounds the blood vessels; causes it to relax
Explanation:
What would the charge be on an ion of boron (B)?
Answer:
3+
Explanation:
Boron belongs to the 3rd group, the Boron family on the periodic table. It has an atomic number of 5. For neutral atoms of Boron, we have 5 electrons in them.
All atoms lose or gain electrons in order to achieve a perfect noble gas configuration which would give them stability. Noble gases are known to be stable and unreactive.
For Boron, it would readily want to lose 3 electrons so as to mimic a Helium, He atom. Helium is the first element in the noble gas series.
When Boron loses 3 electrons, a net charge of 3+ is left on the atom of Boron.
What kind of relationship is shown in this picture
Answer:
The relationship shown is cordial relationship
if a gas occupies at 5.40 L at a pressure of 1.25atm, what will be its volume at a pressure of 3.00 atm? (Show work)
Answer:
Explanation:
Givens
P = 1.25 atm
V = 5.4 L
P1 = 3 atm
V1 = ??
Formula
The basic formula is P*V = P1 * V1
Solution
1.25 * 5.4 = 3 * V1
6.75 = 3*V1
6.75 /3 = 3*V1/3
2.25 = V1
Each Thursday the 11 kindergarten students in Miss Goodson's class are each allowed one slice of pie, one cup of orange juice, and two doughnut holes. The leftovers will be given to the custodian on the night shift.
How many slices of pie are left for the custodian?
slices of pie
How many cups of orange juice are left for the custodian?
cups of orange juice
How many doughnut holes are left for the custodian?
donut holes
How many were there to start off with?
The custodian receives 5 slices of pie, 7 cups of orange juice, and 11 doughnut holes as leftovers.
To calculate the leftovers for the custodian, we must first calculate how many items the students consume and subtract that from the total provided by the caterer:
Pies: There are 2 pies, each cut into 8 slices, for a total of 16 slices. With 11 students, 11 slices will be used, leaving 5 slices for the custodian.Orange juice: There are 18 cups of orange juice and each of the 11 students gets one cup, leaving 7 cups for the custodian.Doughnut holes: There are 33 doughnut holes. Each student eats 2 doughnut holes, so 11 students will consume a total of 22 holes, leaving 11 doughnut holes for the custodian.Oil is a natural resource that is found inside of Earth. Oil can be used
Answer:
ti make gas to make things work and for stalk on the market
Explanation:
How many protons and electrons are present in Pb2+
Answer:
The number of protons of the Pb is 82.
The number of electrons of the Pb²⁺ is 80.
Explanation:
Each chemical element is characterized by the number of protons in its nucleus, which is called the atomic number Z.
The atomic number is used to classify the elements within the periodic table of the elements. In it, you can read in the upper left. In this case, the lead Pb has an atomic number of 82. This indicates that the number of protons of the Pb²⁺ is 82.
In every electrically neutral atom the number of protons in the nucleus is equal to the number of electrons in their orbitals. But in this case it is a cation, that is, it is a positively charged ion. A cation is formed when electrons are lost (which have a negative charge), thus acquiring the positive charge ion. In this case then, Pb²⁺ indicates that the cation has a +2 charge. So this means that 2 electrons have been lost. So, if it were electrically neutral, the lead Pb would have 82 electrons, but with the loss of two of its electrons, the number of electrons of the Pb²⁺ is 80.
There are 82 protons and 80 electrons in one Pb²⁺ ion. Lead (Pb) has an atomic number of 82.
The atomic number of an element represents the number of protons in its nucleus. Since lead (Pb) has an atomic number of 82, it means that a neutral lead atom has 82 protons.
When the Pb²⁺ ion is formed, it means that the atom has lost two electrons. The +2 charge indicates that the atom now has two more protons than electrons. Since electrons have a negative charge, losing two of them results in a net positive charge on the ion.
Since a neutral lead atom has 82 electrons, subtracting two electrons from it gives us 80 electrons in the Pb²⁺ ion. However, the number of protons remains the same at 82. The loss of electrons creates a positive charge, and the number of protons determines the element's identity.
In summary, the Pb²⁺ ion has 82 protons and 80 electrons. The 2+ charge indicates the loss of two electrons, resulting in a net positive charge on the ion.
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What is true about the relative concentrations of hydrogen ions or hydroxide ions in an acidic solution?
a
Hydrogen-concentration is less
b
Hydroxide-ion concentration is greater
c
The concentrations are equal
d
Hydroxide-ion concentration is less
Hydroxide ion concentration is less this statement is true about the relative concentration of hydrogen ions or hydroxide ions in an acidic solution.
Hence, Option (D) is correct answer.
What is pH ?pH is used to measure whether the substance is acidic, basic or neutral and the range is 0 - 14. If the pH is less than 7 then the solution is acidic in nature. If the pH is more than 7 then the solution is basic in nature. If the pH is equal to 7 then the solution is neutral in nature.
What is concentration of hydrogen ion or hydroxide ion in acidic solution ?Acidic solution means the pH of the solution is less than 7. When the solution has pH less than 7 it shows that the hydrogen ion concentration is higher than the hydroxide ion concentration.
Thus, from the above conclusion we can say that Hydroxide ion concentration is less this statement is true about the relative concentration of hydrogen ions or hydroxide ions in an acidic solution.
Hence, Option (D) is correct answer.
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In an acidic solution, the concentration of hydrogen or hydronium ions is greater, and as a result, the concentration of hydroxide ions is less.
Explanation:In an acidic solution, the concentration of hydrogen ions (H+) or hydronium ions (H3O+) is greater than the concentration of hydroxide ions (OH-). This is due to the ionization of the acid in water, which adds more hydrogen ions into the solution, leading to a proportionally lower concentration of hydroxide ions. As per Le Châtelier's principle, the reaction equilibrium of water autoionization shifts to the left, which reduces the concentration of hydroxide ions. Therefore, the correct answer is d: Hydroxide-ion concentration is less.
A weather balloon contains 1.10X10 to the power of 5 mol of helium and has a volume of 2.70x10 to the power of 6 L at 1.00 atm pressure. Calculate the temperature of the helium
Answer:
299.14 K or 26°C
Explanation:
The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas.
The ideal gas law is often written as
PV = nRT
where P ,V and T are the pressure, volume and absolute temperature;
n is the number of moles of gas and R is the ideal gas constant.
n=1.10 x 10^5 mol
V= 2.70 x 10^6 L
P= 1.00 atm= 101.325 kPa
R= 8.314 kPa*L/ mol*K
when the formula is rearranged, T=PV/ nR
T = (101.325kPa * 2.70 x 10^6 L)/ (1.10 x 10^5 mol * 8.314 kPa*L/ mol*K)
T = 299.1421917 K
or
T = 299.14 - 273.15 = 25.99 = 26°C
Using the Ideal Gas law, we find the temperature T = ((1.00 atm)*(2.70x10^6 L))/((1.10x10^5 mol)*(0.0821 L.atm/K.mol)). Calculating that gives you the temperature (in Kelvin) of the helium in the balloon.
Explanation:In that case, you're being asked to find the temperature of helium inside a weather balloon. The Ideal Gas Law (PV=nRT) will be useful here, where P is the pressure (1 atm), V is the volume (2.7x10 to the power of 6 L), n is the number of moles of helium (1.10x10 to the given power of 5 mol), R is the gas constant (0.0821 L.atm/K.mol) and T is the temperature which we need to calculate.
So, the Ideal Gas Law becomes: (1.00 atm)*(2.70x10^6 L) = (1.10x10^5 mol)*(0.0821 L.atm/K.mol)*T
Solving for T by isolating it on one side gives T = ((1.00 atm)*(2.70x10^6 L))/((1.10x10^5 mol)*(0.0821 L.atm/K.mol))
Calculating that should give you the temperature (in Kelvin) of the helium in the balloon.
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what are the main risk and main benefit when a society uses energy from nuclear fission?
a. risk of harm to flying animals; benefit of reducing greenhouse gases
b. risk of high greenhouse gas and particle emissions; benefit of reducing short-term costs
c. risk of groundwater contamination; benefit of using a renewable resource
d. risk from radioactive material; benefit of obtaining low-cost energy
Answer:
D.
Explanation:
Nuclear energy does not have greenhouse gas emissions. The emissions produced by nuclear fission plants are similar to renewable energy sources.The generation of power using nuclear energy does not affect air quality thus providing a clean source of energy.Nuclear energy originates from radioactive material which are harmful to living organisms.
Answer:
D. risk from radioactive material; benefit of obtaining low-cost energy
Explanation:
I just took the test. Ap*x
what happens to sodium sulphate in water
Answer:
It dissolves into the water
Na₂SO₄ + H₂O → 2Na₊_{aq} + SO₄²-_{aq}
Hope this helps :)
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5INGH
Explanation:
help me with this please i need chem help lol
Answer:
[tex]\boxed{\text{1. 0.47 mol; 2. 0.046 mol; 3 (a) 11.6 mol, 15.4 mol, (b) 2.31 mol, 3.08 mol, 0.770 mol}}[/tex]
Explanation:
1. Moles of Na
(a) Balanced equation
2Na + 2H₂O ⟶ 2NaOH + H₂
(b) Calculation
You want to convert moles of H₂ to moles of Na
The molar ratio is 2 mol Na:1 mol H₂
Moles of Na = 4.0 mol H₂ × (2 mol Na/1 mol H₂) = 8.0 mol Na
You need [tex]\boxed{ \text{8.0 mol of Na}}[/tex] to form 4.0 mol of H₂.
2. Moles of LiCl
(a) Balanced equation
2LiBr + Cl₂⟶ 2LiCl + Br₂
(b) Calculation
You want to convert moles of LiBr to moles of LiCl
The molar ratio is 2 mol LiBr:2 mol LiCl
Moles of LiCl = 0.046 mol LiBr × (2 mol LiCl/2 mol LiBr) = 0.046 mol LiCl
The reaction will produce [tex]\boxed{ \text{0.046 mol of LiCl}}[/tex].
3. Combustion of propane
C₃H₈ +5O₂ ⟶ 3CO₂ +4H₂O
(a) Moles of CO₂ and H₂O
Moles of CO₂ = 0.647 mol O₂ × (3 mol CO₂/1 mol C₃H₈) = 11.6 mol CO₂
Moles of H₂O = 3.85 mol O₂ × (4 mol CO₂/1 mol C₃H₈) = 15.4 mol H₂O
The reaction produces [tex]\boxed{ \text{11.6 mol of CO}_{2}}[/tex] and [tex]\boxed{ \text{15.4 mol of H}_{2}\text{O}}[/tex].
(b) Moles from O₂
Moles of CO₂ = 3.85 mol O₂ × (3 mol CO₂/5 mol O₂) = 2.31 mol CO₂
Moles of H₂O = 3.85 mol O₂ × (4 mol CO₂/5 mol O₂) = 3.08 mol H₂O
Moles of C₃H₈ = 3.85 mol O₂ × (1 mol C₃H₈/5 mol O₂) = 0.770 mol C₃H₈
The reaction produces [tex]\boxed{ \text{2.31 mol}}[/tex] of CO₂, [tex]\boxed{ \text{3.08 mol}}[/tex] of H₂O, and consumes [tex]\boxed{ \text{0.770 mol}}[/tex] of C₃H₈.
Atoms,which are always neutral in electric charge, contain electrons as well as protons and neutrons. An electron has an electrical charge of -1. If an atom has three electrons, infer how many protons it has.
Answer:
3
Explanation:
Since the atom has three electrons, it has a -3 electrical charge. Since atoms are neutral, 3 protons are needed to get the charge back to 0.
An atom maintains a neutral charge when it has an equal number of protons and electrons. Therefore, an atom with three electrons will have three protons. This principle is integral to the formation of ions when atoms gain or lose electrons.
Explanation:An atom is characterized by having an equal number of protons and electrons, thus maintaining a neutral charge. Protons carry a positive charge and electrons a negative one. Keeping in mind that a neutral atom has an equal number of both, if an atom has three electrons, it also has three protons.
In Chemistry, we know that atoms are neutral if they contain the same number of positively charged protons and negatively charged electrons. When the counts of these particles are unequal, the atom is electrostatically charged and is called an ion. This charge is calculated as: Atomic charge = number of protons - number of electrons.
For instance, if a neutral sodium atom (Z = 11) with 11 electrons loses one, it forms a cation with a 1+ charge (11 - 10 = 1+). Conversely, a neutral oxygen atom (Z = 8) gaining two electrons becomes an anion with a 2- charge (8 - 10 = 2-).
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What does ethylene glycol do to the solution in a vehicle’s radiator? It raises the boiling point and lowers the freezing point. It lowers the boiling point and lowers the freezing point. It lowers the boiling point and raises the freezing point. It raises the boiling point and raises the freezing point.
Answer:
It raises the boiling point and lowers the freezing point.
Explanation:
It is used as antifreeze in the cooling circuits of internal combustion engines, that is, it is used to reduce the melting point of the solution.
By adding ethylene glycol I'm not only bringing the melting point to -13°C, but the boiling point of ethylene glycol is 197°C.
since these substances not only lower the freezing point but also increase the boiling point, they are also called a colligative agent
Answer:
The correct option is A) It raises the boiling point and lowers the freezing point.
Explanation:
Consider the provided information.
Ethylene glycol is often used for convective heat transfer.
The freezing point of pure ethylene glycol is about −12° C and boils at 198° C.
Due to the higher boiling point and antifreeze properties, it is used in a vehicle’s radiator.
Therefore, the correct option is A) It raises the boiling point and lowers the freezing point.
Arrange the levels of ecological organization from smallest to largest. (ecosystem, population, community, organism)
Answer:
organism, population, community, ecosystem
Explanation:
Answer: Organism, Population, Community, and lastly Ecosystem
Explanation: Organism is one living thing. Population is a group of organisms of one type that live together. Communities are populations that live together in an area. Ecosystem is a community with its non living surroundings.
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How to remember the first 20 elements of the periodic table?
The way the brain works is that you learn from repetition, the more you do something the better you get at it. So the more you review the first 20 elements on the periodic table, the more often you'll be able to remember it until you're about to recount them without hardly thinking of it.
My advice to you is to grab some pieces of paper. Cut them up into sixths until you have twenty of them, then write down on each smaller piece of paper the numbers 1 up to 20. Then on the other side of the paper, write down the element. Do this in accordance to their position on the periodic table. Then spend some time guessing as to what element is on the other side of the numbered paper. You'll start guessing, "the first element is Hydrogen. The second element is Helium." And so on. Rinse and repeat until you're able to guess the element depending on its placement on the periodic table. Good luck!
Happy. – H Hydrogen
Henry – He Helium
Lives – Li Lithium
Beside – Be Beryllium
Born – B Boron
Cottage – C Carbon
Near – N Nitrogen
Our – O Oxygen
Friend – F Fluorine.
Nelly – Ne Neon
Nancy – Na Sodium
Mg – Mg Magnesium
Allen – Al Aluminum
Silly – Si Silicon
Patrick – P Phosphorus
Stays – S Sulphur
Close – Cl Chlorine
Arthur – Ar Argon
Kisses – K Potassium
Carrie – Ca Calcium
Hope this helps :)
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Strong conductivity of plasma allows it to act and react as ______________ and ____________ fields
Answer:
I think it is high and electric
Explanation:
Answer:
strong conductivity of plasma allows it to act and react as electric and magnetic fields.