1. 0.2755 M
2. 1.574 M
3. 4.5 moles
Explanation:
Molality is defined as the number of moles of solute dissolved in a kg of solvent;
1)
If 0.135 moles of CO2 is dissolved in 490mL of water, how much moles are in 1000 mL (1 kg) of water;
0.135 : 490
x : 1000
490x = 1000 * 0.135
x = 135 /490
x = 0.2755 moles
= 0.2755 M
2)
If 23g of NaCl are dissolved in 250g of water, how much NaCl in dissolve in 1000g (1kg) of water;
23 : 250
x : 1000
250x = 1000 * 23
x = 23000/250
x = 92 g
To find many moles of NaCl are in 92g (Remember molar mass of NaCl is 58.44 g/mol) ;
92/ 58.44
= 1.574 moles
= 1.574 M
3)
A 3 M HCl solution means there are 3 moles of HCl in 1L (1 kg) water.
3 : 1
x : 1.5
x = 1.5 * 3
x = 4.5
= 4.5 moles
Which of th following is true for a parallel circuit
Answer:
B. The voltage is the same across all resistors in the circuit.Explanation:
The answer choices are:
A.The current is the same across all resistors in the circuit.B.The voltage is the same across all resistors in the circuit.C. As more resistors are added, the current will decrease.D. The sum of the voltage drops will equal the total voltage. SolutionIn a simple parallel circuit, each component (resistor) is connected directly to the battery forming different branches or pathways to the current.
Thus, the ends of each resistor receives the total potential difference or voltage from the battery, which is what the statement B. asserts. Hence, statement B is true.
On the other hand, the current will split among the different pathways, following Ohm's law: the greater the resistance of the resistor the lower the current. Thus, the statement A is false.
For a parallel circuit, the total resistance decreases as more resistors are added, which means that, again following Ohm's law, the current will increase, contradicting the statement C. Thus, the statement C is false.
It is in the series circuit that 'the sum of the voltage drops will equal the total voltage"; in a parallel circuit the voltage drop is the just one and the same for each resistor. Thus, the statement D is false,too.
Calculate the approximate volume of a 0.6000mol sample of gas at 288.15K and a pressure of 1.10atm.
Answer:
The volume of the sample of the gas is found to be 12.90 L.
Explanation:
Given pressure of the gas = P = 1.10 atm
Number of moles of gas = n = 0.6000 mole
Temperature = T = 288.15 K
Assuming the volume of the gas to be V liters
The ideal gas equation is shown below
[tex]\textrm{PV} =\textrm{nRT} \\1.10 \textrm{ atm}\times V \textrm{ L} = 0.6000 \textrm{ mole}\times 0.0821 \textrm{ L.atm.mol}^{-1}.K^{-1}\times 288.5\textrm{K} \\\textrm{V} = 12.90 \textrm{ L}[/tex]
Volume occupied by gas = 12.90 L
What charge will an ion of phosphorus form?
Answer:
A charge of -3
Explanation:
If you look on a periodic table you will find that phosphorus is 3 elements away from the nearest noble gas argon. This means that phosphorus would prefer a charge of -3!
Answer:typically it will be -3
Explanation:
It prefers to take up 3 electrons and thereby become phosphide with a -3 charge. since it is a nonmetal it will take up electrons making it negative as an ion. In order to fill up its last shell, to become stable, to form an octet it will need 3 added electrons which will give it that -3 charge. An atom of phophorus will be neutral, An ion of phsphorus will have a -3 charge.
QUESTION 1: Using the experimental data, calculate the standard reduction potential for each metal, and organise them into a standard reduction table. Assume E° for B is 0V.
QUESTION 2: Deduce which two metals would produce the highest cell potential in a galvanic cell. Give reasons for your conclusion.
Final answer:
To calculate the standard reduction potential for each metal and organize them into a standard reduction table, we can use the formula Ecell = Ered - Eox. The standard potential for Q is -0.38V and for G is +0.72V.
Explanation:
To calculate the standard reduction potential for each metal, we can use the formula Ecell = Ered - Eox. Given the reduction potentials for Q and G, we can assume the reduction potential for Q is +0.38V and the reduction potential for G is -0.72V. Since Q is oxidized when connected to the standard hydrogen electrode, its standard potential is negative (-0.38V). On the other hand, since G is reduced when connected to the standard hydrogen electrode, its standard potential is positive (+0.72V).
Organizing the metals into a standard reduction table:
MetalStandard Reduction Potential (E°)Q-0.38VG+0.72V
Metal B has the highest standard reduction potential (0.85 V), and metal E follows closely (0.63 V). B-E galvanic cell would yield the highest potential due to their strong reduction tendencies.
To calculate the standard reduction potential for each metal, you can use the Nernst equation:
[tex]E_{\text {cell }}^{\circ}=E_{\text {cathode }}^{\circ}-E_{\text {anode }}^{\circ}[/tex]
where [tex]E_{\text {cell }}^{\circ}[/tex] is the standard cell potential, [tex]E_{\text {cathode }}^{\circ}[/tex] is the standard reduction potential of the cathode, and [tex]E_{\text {anode }}^{\circ}[/tex] is the standard oxidation potential of the anode.
First, let's assign oxidation numbers and write the balanced half-reactions for each cell:
1. [tex]\mathrm{A}(\mathrm{s})+\mathrm{B}^{2+}(\mathrm{aq}) \rightarrow \mathrm{A}^{2+}(\mathrm{aq})+\mathrm{B}(\mathrm{s})[/tex]
Reduction half-reaction: [tex]\mathrm{B}^{2+}(\mathrm{aq})+2 e^{-} \rightarrow \mathrm{B}(\mathrm{s})[/tex]
[tex]E_{\text {cathode }}^{\circ}[/tex] = 0.85
[tex]E_{\text {anode }}^{\circ}[/tex] = 0
2. [tex]\mathrm{B}^{2+}(\mathrm{aq})+\mathrm{C}(\mathrm{aq}) \rightarrow \mathrm{B}(\mathrm{s})+\mathrm{C}^{2+}(\mathrm{aq})[/tex]
Reduction half-reaction: [tex]\mathrm{C}(\mathrm{aq})+2 e^{-} \rightarrow \mathrm{C}^{2+}(\mathrm{aq})[/tex]
[tex]E_{\text {cathode }}^{\circ}[/tex] = −0.24
[tex]E_{\text {anode }}^{\circ}[/tex] = 0
3. [tex]2 \mathrm{D}^{+}(\mathrm{aq})+\mathrm{C}(\mathrm{s}) \rightarrow 2 \mathrm{D}(\mathrm{s})+\mathrm{C}^{2+}(\mathrm{aq})[/tex]
Reduction half-reaction: [tex]\mathrm{C}(\mathrm{s})+2 e^{-} \rightarrow \mathrm{C}^{2+}(\mathrm{aq})[/tex]
[tex]E_{\text {cathode }}^{\circ}[/tex] = 0
[tex]E_{\text {anode }}^{\circ}[/tex] = 0.58
4. [tex]\mathrm{B}(\mathrm{s})+\mathrm{B}^{2+}(\mathrm{aq}) \rightarrow \mathrm{B}^{2+}(\mathrm{aq})+\mathrm{B}(\mathrm{s})[/tex]
Reduction half-reaction: [tex]\mathrm{B}^{2+}(\mathrm{aq})+2 e^{-} \rightarrow \mathrm{B}(\mathrm{s})[/tex]
[tex]E_{\text {cathode }}^{\circ}[/tex] = 0
[tex]E_{\text {anode }}^{\circ}[/tex] = 0
5. [tex]\mathrm{B}(\mathrm{s})+\mathrm{E}^{2+}(\mathrm{aq}) \rightarrow \mathrm{B}^{2+}(\mathrm{aq})+\mathrm{E}(\mathrm{s})[/tex]
Reduction half-reaction: [tex]\mathrm{E}^{2+}(\mathrm{aq})+2 e^{-} \rightarrow \mathrm{E}(\mathrm{s})[/tex]
[tex]E_{\text {cathode }}^{\circ}[/tex] = 0.63
[tex]E_{\text {anode }}^{\circ}[/tex] = 0
Now, let's calculate the standard reduction potentials for each metal:
[tex]\begin{aligned}& E_{\mathrm{B}}^{\circ}=0.85-0=0.85 \\& E_{\mathrm{C}}^{\circ}=-0.24-0=-0.24 \\& E_{\mathrm{D}}^{\circ}=0-0.58=-0.58 \\& E_{\mathrm{B}}^{\circ}=0 \\& E_{\mathrm{E}}^{\circ}=0.63-0=0.63\end{aligned}[/tex]
The two metals that would produce the highest cell potential in a galvanic cell are the ones with the highest standard reduction potentials. In this case, metals B and E have the highest reduction potentials, so a galvanic cell composed of B and E would have the highest cell potential. The reason is that a higher standard reduction potential indicates a stronger tendency to be reduced, and therefore, a higher cell potential in a galvanic cell.
1) ____ NaCl + ____ KOH ____ NaOH + ____ KCl
2) ____ MgO + ____ Li2SO4 ____ MgSO4 + ____ Li2O
3) ____ H2O ____ H2 + ____ O2
4) ____ RbF + ____ Be(NO3)2 ____ RbNO3 + ____ BeF2
5) ____ Ag +____ Cu(NO3)2 ____ AgNO3 + ____ Cu
6) ____ CO2 + ____ Cl2 ____ CCl4 + ____ O2
7) ____ CuSO4 + ____ HCN ____ Cu(CN)2 + ____ H2SO4
8) ____ Ga2O3 + ____ Li ____ Li2O + ____ Ga
9) ____ BaF2 + ____ Na2S ____ BaS2 + ____ NaF
10) ____ NH3 ____ N2 + ____ H2
please solve as many as you can, the boxes are arrows
Answer:
hope it's helpful to you .
your 9th question is wrong but I did it correctly
it's not BaS2 it's BaS
The student's inquiry involved balancing a series of chemical equations, a fundamental concept in stoichiometry. Each balanced equation ensures that there is the same number of each element's atoms on the reactant side as on the product side, in accordance with the law of conservation of matter.
Explanation:The questions you've posed involve stoichiometry, a field in chemistry that quantifies the relationships of different substances in a chemical reaction. Balancing chemical equations involves ensuring the conservation of atoms (each element in reactants should be equal to the count of the same element in products). Here are the balanced equations:
2 NaCl + 2 KOH → 2 NaOH + K2Cl2MgO + Li2SO4 → MgSO4 + 2Li2O2 H2O → 2 H2 + O22 RbF + Be(NO3)2 → 2 RbNO3 + BeF22 Ag + Cu(NO3)2 → 2 AgNO3 + CuNo reaction occurs in this case.3 CuSO4 + 6 HCN → 3 Cu(CN)2 + 3 H2SO46 Li + Ga2O3 → 3 Li2O + 2 Ga2 Na2S + BaF2 → BaS + 4 NaF2 NH3 → N2 + 3 H2Learn more about Balancing chemical equations here:
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| Solve
-15 =5m/7 find m
Answer:
m= −21
Explanation:
Solve for m by simplifying both sides of the equation, then isolating the variable. m= −21
What information does a net ionic equation give?
O
A. It lists only the spectator ions that are present.
B. It lists only the components that are ions.
O
C. It lists only the substances that are changed.
D. It lists only the aqueous components of the reaction.
Answer:
C. It lists only the substances that are changed.
Explanation:
Balanced Chemical equation:
HClO₂(aq) + NaOH(aq) → H₂O(l) + NaClO₂ (aq)
Ionic equation:
H⁺(aq) + ClO₂⁻(aq) + Na⁺(aq) + OH⁻(aq) → H₂O(l) + Na⁺(aq) + ClO₂⁻ (aq)
Net ionic equation:
H⁺(aq) + OH⁻(aq) → H₂O(l)
The ClO₂⁻(aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation. The water can not be splitted into ions because it is present in liquid form. This'e why it is written in net ionic equation.
Spectator ions:
These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.
Final answer:
A net ionic equation lists only the substances that change during a reaction, excluding spectator ions that do not participate in the chemical process. Therefore, the correct answer is C: It lists only the substances that are changed.
Explanation:
A net ionic equation is a chemical equation that shows only the species that actually participate in the reaction. These species are the ions that undergo a chemical or physical change during the reaction, which is different from the spectator ions that do not participate in the reaction. Spectator ions are present in the solution before and after the chemical reaction and do not undergo any change, so they are not included in the net ionic equation.
Correctly answering the student's question, a net ionic equation provides information about option C: It lists only the substances that are changed. This type of equation demonstrates the actual chemical change between the ionic compounds, excluding all the spectator ions that remain unchanged during the reaction process.
if a sample of gas at 25.2°C has a volume of 536 ml at 637 torr, what will its volume be if the pressure is increased to 712 torr?
Answer:
V = 479.6 mL
Explanation:
assuming ideal gas:
PV = RTn∴ T = 25.2°C ≅ 298.2 K.........remains constant
∴ P1 = 637 torr = 0.8382 atm
∴ V1 = 536 mL = 0.536 L
∴ R = 0.082 atm.L/K.mol
⇒ n = (P1V1)/(RT) = ((0.8382 atm)*(0.536 L))/((0.082 atmL/Kmol)*(298.2K))
⇒ n = 0.0184 mol......remains constant
∴ P2 = 712 torr = 0.936842 atm
⇒ V2 = RTn/P2 = [(0.082atmL/Kmol)*(298.2K)*(0.0184mol)]/(0.936842atm)
⇒ V2 = 0.4796 L
Boyle's Law can be applied in this situation to show that when pressure on a gas sample increases, its volume decreases, assuming a constant temperature. By substituting the given values into the Boyle's Law formula, we find that the new volume, with increased pressure, is approximately 478 mL.
Explanation:The volume of gas changing with pressure can be explained by Boyle's Law, which states that the pressure and volume of a gas have an inverse relationship when temperature is held constant. In this case, we can set up an equation based on Boyle's Law (P1V1 = P2V2), where P1 and V1 represent the initial pressure and volume, and P2 and V2 represent the final pressure and volume.
To solve for V2, you can rearrange the formula to: V2 = (P1V1) / P2. Substituting the given values into the formula:
V2 = (637 torr * 536 mL) / 712 torr = 478 mL approximately.
So, if the pressure is increased to 712 torr, the volume of the gas decreases to roughly 478 ml.
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What mass of K2SO4 What do you need to prepare 1200 g of an 8% K2SO4 m/m solution
Answer:
96 grams are required.
Explanation:
Given data:
Mass of K₂SO₄ required = ?
Mass of K₂SO₄ from = 1200 g of 8%
Solution:
Formula:
m/m% = mass required / mass given
Now we will put the values:
8%= x / 1200 g
8/100 = x / 1200 g
0.08 = x / 1200 g
0.08 × 1200 g= x
x = 96 g
So 96 gram of 1200 g is required.
Which of the following is true?
A
The sun has very little effect on natural cycles.
B
The sun is only helpful and is never dangerous.
The sun is very important, but its rays can also be harmful.
D
The sun is very dangerous and doesn't really support life on Earth.
Answer:
B
Explanation:
The sun can be dangerous but it also helps our Earth in a lot of ways
Final answer:
Answer C is true: The sun is critical for life on Earth, affecting natural cycles and providing necessary energy, but its UV rays can also be harmful to health and influence Earth's climate.
Explanation:
The correct answer is C: The sun is very important, but its rays can also be harmful. The sun radiates light and heat which are essential for the existence of life on Earth. It plays a crucial role in various natural cycles, such as those that regulate climate and weather, and it has enabled the development of all life forms as we know them. However, it is also true that the sun can be dangerous due to its intense ultraviolet (UV) rays, which can cause skin cancer, cataracts, and other health issues. Moreover, changes in the sun's energy can influence Earth's climate, potentially leading to warming or cooling periods.
Write the balanced molecular equation for the reaction of barium hydroxide with perchloric acid. What is the coefficient of H2O?
Answer:
Ba(OH)2 + 2HClO4 —> Ba(ClO4)2 + 2H2O
The coefficient of H2O is 2
Explanation:
Ba(OH)2 + HClO4 —> Ba(ClO4)2 + H2O
Now let us balance the equation as shown below:
There are 2 atoms of Cl on the right and 1 atom on the left. It can be balanced by putting 2 in front of HClO4 as shown below:
Ba(OH)2 + 2HClO4 —> Ba(ClO4)2 + H2O
Now, there are a total of 4 atoms of H on the left and 2 on the right. It is balanced by putting 2 in front of H2O as shown below
Ba(OH)2 + 2HClO4 —> Ba(ClO4)2 + 2H2O
Now, the equation is balanced. From the balanced equation, the coefficient of H2O is 2
The balanced molecular equation for the reaction of barium hydroxide (Ba(OH)₂) with perchloric acid (HClO₄) is:
Ba(OH)₂ + 2HClO₄ -> Ba(ClO₄)₂ + 2H₂O
In this equation, the coefficient of H₂O is 2.
A balanced equation is a chemical equation in which the number of atoms of each element is equal on both sides of the equation. It represents a chemical reaction by showing the reactants on the left side and the products on the right side, with appropriate coefficients to balance the equation.
In a balanced equation, the total mass and the total charge of the reactants are equal to the total mass and total charge of the products. This ensures that the law of conservation of mass and the law of conservation of charge are satisfied.
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Propane burns in oxygen to produce carbon dioxide and steam. Which of the chemical equations matches the reaction above?
A. C3H8 + 5O2 3CO2 + 4H2O
B. C3H8 + 4O2 2CO2 + 4H2O
C. C3H8 + 6O2 2CO2 + 8H2O
D. C3H8 + 6O2 3CO2 + 6H2O
Answer: A
Explanation:
Balancing a chemical reaction, we must take into consideration every element both at the reactant and products side.
Since we were told propane reacts with oxygen to produce steam and carbon dioxide, we already have an idea of how the equation would be just remaining balancing the stoichiometry of the equation.
C3H8 + 5O2 =====》 3CO2 + 4H20
From the equation above,
3 atoms of carbon is present at reactant side and 3 carbon is also at the product side.
8 Hydrogen at reactant = 4 * 2 Hydrogen at product.
10 Oxygen at reactant = 3*2 + 4 oxygen at product
The equation must be balanced because law of conservation of matter must take place in every chemical reaction, matter can neither be created nor destroyed but can change form.
Answer:
A
Explanation:
Propane burns in oxygen to produce carbon dioxide and steam. The chemical equation is written with chemical symbols below:
C3H8 + O2 CO2 + H2O
There are three carbon atoms on the left side, but only one on the right, so we need to put a 3 in front of the carbon dioxide molecule to give three carbons on each side:
C3H8 + O2 3CO2 + H2O
There are eight hydrogen atoms on the left side and two on the right side, so we need to place a 4 in front of the water molecules on the right side:
C3H8 + O2 3CO2 + 4H2O
There are 2 oxygen atoms on the left side and 10 on the right side, so we need to place a 5 in front of the oxygen molecule on the left side:
C3H8 + 5O2 3CO2 + 4H2O
The equation has been balanced.
How much mercury and oxygen could be obtained from 21.7g of mercury (II) oxide
20.06 g of Hg and 1.6 g of O₂
Explanation:
To Find:
Number of Mercury and oxygen that can be obtained from 21.7 g of HgO
First we have to write the balanced equation for the decomposition reaction of Mercury(II) oxide as,
2 HgO (s) → 2Hg(l) + O₂ (g)
21.7 g of HgO = [tex]\frac{21.7 g}{216.59 g / mol}[/tex]
= 0.1 mol of HgO.
As per the above equation, we can find the mole ratio between HgO and Hg is 1: 1 and that of HgO and oxygen is 2:1 .
So amount of Hg produced = 0.1 mol × 200.59 g / mol ( molar mass of Hg)
= 20.06 g of Hg
Amount of oxygen produced = 0.05 mol × 32 g/ mol = 1.6 g of O₂
Thus it is clear that 20.06 g of Hg and 1.6 g of O₂ is obtained from 21.7 g of HgO
Final answer:
From 21.7g of mercury (II) oxide, approximately 20.059 g of mercury and 1.6 g of oxygen can be produced through the decomposition reaction. This calculation uses the stoichiometry of the reaction and the molar masses of the substances involved.
Explanation:
To determine how much mercury and oxygen could be obtained from 21.7g of mercury (II) oxide, we need to consider the decomposition reaction of mercury (II) oxide under standard state conditions:
2HgO(s, red) → 2Hg(l) + O2(g)
By using the molar mass of mercury (II) oxide (216.59 g/mol), we can convert the mass of mercury (II) oxide to moles:
21.7 g HgO × (1 mol HgO / 216.59 g HgO) = 0.1 mol HgO
Following the stoichiometry of the reaction, 0.1 moles of HgO will produce 0.1 moles of Hg and 0.05 moles of O2, since 2 moles of HgO decompose to produce 1 mole of O2. We can then calculate the mass of mercury and oxygen produced:
0.1 mol Hg x (200.59 g Hg/mol) = 20.059 g of Hg
0.05 mol O2 x (32 g O2/mol) = 1.6 g of O2
Therefore, 21.7g of mercury (II) oxide will produce approximately 20.059 g of mercury and 1.6 g of oxygen.
the electrical current in a circuit is measured in which of the following units.
volts
resistance
amperes
pressure
The electrical current in a circuit is measured in amperes (amps). According to Ohm's Law, current (I) equals voltage (V) divided by resistance (R). Understanding these units helps grasp the flow of electricity in circuits.
The electrical current in a circuit is measured in amperes (often abbreviated as amps and symbolized by 'A'). According to Ohm's Law, the electric current (I) can be calculated by dividing the voltage (V) by the resistance (R). These relationships and units help in understanding the flow of electric current in circuits:
Voltage (V) is measured in volts.Resistance (R) is measured in ohms.Electric current (I) is measured in amperes.If 1.30 grams of a protein (non -electrolyte) are added to a 100.0 mL of water, the osmotic pressure of the resulting solution is 0.0074 atm at 298 K. What is the molar mass of the protein ?
Answer:
M = 0.43× 10⁵ g/mol
Explanation:
Given data:
Mass of protein = 1.30 g
Volume of water = 100.0 mL ( 100/1000 =0.1 L)
Pressure of solution = 0.0074 atm
Temperature = 298 K
Molar mass of protein = ?
Solution:
Formula:
PV = nRT
n = PV / RT
n = 0.0074 atm ×0.1 L / 0.0821 atm. L / mol.K × 298 K
n = 0.00074 / 24.5 /mol
n = 3.0 × 10⁻⁵ mol
Molar mass of protein:
Number of moles = mass / molar mass
3.0 × 10⁻⁵ mol = 1.30 g/ M
M = 1.30 g/ 3.0 × 10⁻⁵ mol
M = 0.43× 10⁵ g/mol
Describe the difference between Al3+
and N3-
Why do reactivity increases on moving from top to bottom in group 2 of modern periodic table?
Answer:
that's because....
group 1 (e.g Na, K) those tend to lose one electron to gain noble gas electron configuration.
they can achieve that by just losing one electron from their outer shell.
as you go down the group 1, element gets bigger in size, which means there is more space between nucleus (which is in center of atom) and electron of outer shell. the more far away they are the less attraction force between them.
so its easier for potassuim to lose one electron than for lithuim.
so that means potassium will easily give up 1 electron to react with non metal or other element therefore it is more reactive than lithuim
but in case of non metal, the opposite happens but simple to understand.
as you go down the group 7 (halogen- Cl, Br, I) element will get bigger therefore force between nucleus and outer electron is getting smaller. they have to gain 1 electron in order to fill the outer shell (to gain noble gas electron configuration.)
as florine is more smaller in size than clorine it is more reactive because florine has more tendency to pull extra electron from metal or other element towards its side. so it easily gain 1 electron to react.
how is energy transferred to or from an object if the kinetic energy changes
100 Points!! PLEASE HELP!! PLEASE!! PLEASE!!
The Universe is believed to have been formed from a very dense fireball _____________ of years ago. As the fireball
expanded and cooled stars and galaxies formed. The fireball explosion is often called the ___ ________. The explosion
threw all the material outwards; that is why scientists believe the universe is getting bigger or ____________. Scientists
have confirmed that the Universe is expanding by examining the light given off by stars. Astronomers now know that the
distance to the furthest galaxies is becoming greater as these galaxies are moving away the __________. Stars are
produced from gas clouds or ___________, which contain mainly the element ____________. The type of star produced
depends on the mass of the star. Red _________ are stars formed which have a mass _________ than that of our
____________ .
Hydrogen is the __________ of all stars. During nuclear fusion the hydrogen molecules combine producing
____________, releasing lots of ____________ in the process. How quickly the hydrogen is used up depends on the size
of the star. Massive stars burn hydrogen very quickly. Additional nuclear fusion reactions can convert helium into
elements with larger atoms, for example lithium. However the elements with the largest atoms only form when a star
explodes as a _______________
The amount of energy given out by a star, its luminosity, varies considerably. ____________ dwarfs are stars that have a
very low luminosity, about one hundredth of the Sun. Super giant stars which are very large red giant stars, can give out
as much energy as 1,000,000 Suns. Some scientists believe that our Solar System was once a binary star system. The Sun
was the __________ of the two stars and burnt its fuel slowly, lasting millions of years. The larger star used up all its fuel
and destroyed itself in a supernova explosion, leaving the Sun behind.
The Sun is a very stable star. In a few billion years from now the Sun will use up its fuel supply and start to change. It will
probably expand and form a red giant. Finally, it may form a white dwarf or a ____________ star. When this happens
there will no longer be life on the Earth, but by then we should have found new _________ around other stars.
Your answer choices are fuel, nebula, expanding, less, hydrogen, smaller, energy, Sun, quickest, supernova, homes, white, neutron, giants,
helium, Big Bang, billions
Answer:
(13) billions
Big bang
expanding
quickest
nebula
hydrogen
giants
less,sun
fuel
helium
energy
supernova
white
smaller
neutron
planets/homes
Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. What are the coefficients for this reaction?
Answer:
C5H12 + 8O2 —> 5CO2 + 6H2O
The coefficients are 1, 8, 5,6
Explanation:
The equation for the reaction is given below:
C5H12 + O2 —> CO2 + H2O
Now let us balance the equation. This is illustrated below:
There are 5 atoms of C on the left side and 1atom on the right side. It can be balance by putting 5 in front of CO2 as illustrated below:
C5H12 + O2 —> 5CO2 + H2O
There are 12 atoms of H on the left side and 2atoms on the right. It can be balance by putting 6 in front of H2O as illustrated below:
C5H12 + O2 —> 5CO2 + 6H2O
There are a total of 16 atoms of O on the right side and 2atoms on the left side. It will be balance by putting 8 in front of O2 as illustrated below:
C5H12 + 8O2 —> 5CO2 + 6H2O
Now we see clearly that the equation is balanced as the number of atoms of the different elements on both sides of the equation are the same.
The coefficients are 1, 8, 5,6
This help with this chart
Answer:
Explanation:
Atomic mass is the sum of number of protons and neutrons while atomic number is the number of protons or electrons.
A neutral atom has equal number of protons and electrons that's why atomic number could be either number of protons or electrons.
Element Symbol Atomic# Mass# Protons Neutrons
Mercury Hg 80 200 80 120
Solution:
number of neutrons = mass number - atomic number
number of neutrons = 200 - 80
number of neutrons = 120
Element Symbol Atomic# Mass# Protons Neutrons
Tungsten W 74 184 74 110
Solution:
number of neutrons = mass number - atomic number
number of neutrons = 184 - 74
number of neutrons = 110
Element Symbol Atomic# Mass# Protons Neutrons
Sodium Na 11 23 11 12
Solution:
number of neutrons = mass number - atomic number
number of neutrons = 23 - 11
number of neutrons = 12
Element Symbol Atomic# Mass# Protons Neutrons
Antimony Sb 51 122 51 71
Solution:
number of neutrons = mass number - atomic number
number of neutrons = 122 - 51
number of neutrons = 71
Element Symbol Atomic# Mass# Protons Neutrons
Silver Ag 47 108 47 61
Solution:
number of neutrons = mass number - atomic number
number of neutrons = 108 - 47
number of neutrons = 61
2. When a teaspoonful of sugar is added to water in a beaker,
the sugar dissolves. The resulting mixture is
1) a compound
2) a solution
3) a suspension
4) an emulsion
The mixture is a solution
Its a solution because two substances mixed
In which of the following substances does a beam of light travel the fastest?
A. water
B. plastic
C. glass
D. air
Answer:
d
Explanation:
The light is an electromagnetic radiation which can be perceived by our human eye. The beam of light travel fastest in air. The correct option is D.
What is light?The light is defined as an electromagnetic radiation which help us to see the objects. It is composed of small packets of energy called photons. The light always moves in a straight line. Light travels at a faster rate than sound waves.
The speed of light is found to be 3 × 10⁸ m/s. Light does not require a physical medium for the propagation. It is known as a transverse wave which travels without the use of medium.
According to Einstein's theory of relativity, nothing can travel faster than light. When light is incident on any surface, the particles of light collide with the surface and thereby reflection and refractions occur.
Thus the correct option is D.
To know more about light, visit;
https://brainly.com/question/30749500
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What is the molar mass of the anhydrous
compound? Answer using four significant figures.
36.02 g/mol
120.15 g/mol
156.12 g/mol
Answer: 120.15
Explanation:
Answer:
120.15
Explanation:
Look at the periodic table
2Al + 3H2SO4->Al2(SO4)3+H2
a) how many grams of aluminum sulfate would be formed if 250g h2SO4 completely reacted with aluminum
287.39 grams of Al2(SO4)3 is formed if 250g H2SO4 completely reacted with aluminum.
Explanation:
Balanced chemical equation:
2Al + 3H2SO4->Al2(SO4)3+H2
Data given:
atomic mass of Al2(SO4)3 = 342.14 gram/mole
mass of H2SO4 given = 250 gram
atomic mass of one mole of H2SO4 = 98.079 grams/mole
number of moles = [tex]\frac{mass}{atomic mass of one mole}[/tex]
number of moles = [tex]\frac{250}{98.079}[/tex]
number of moles = 2.54 moles
from the equation it can be seen as
3 moles of H2SO4 will react to give 1 mole Al2(SO4)3
2.54 moles of H2SO4 will react to give x moles of Al2(SO4)3.
[tex]\frac{1}{3}[/tex]= [tex]\frac{x}{2.54}[/tex]
x = 0.84 moles of Al2(SO4)3 is formed.
to calculate mass of the Al2(SO4)3 = Number of moles x atomic weight of one mole
= 0.84 x 342.14
= 287.39 grams of Al2(SO4)3 is formed.
When turbidity currents deposit graded beds of mud and sand on the ocean floor, what type of rock is formed?
A. Sedimentary
B. Metamorphic
C. Igneous basalt
D. Igneous granite
The chemical equation below shows the reaction of glucose and oxygen.
C6H12O6 + 6O2 -> 6CO2 + 6H2O + 36ATP
Which process does this equation represent and two of its products would be the reactants to which process?
⦁ Photosynthesis, aerobic respiration
⦁ Aerobic respiration, photosynthesis
⦁ Anaerobic respiration, photosynthesis
⦁ Nitrogen fixation, aerobic respiration
Which of the statements is correct regarding catalysts ( click 4 that apply )
Catalyst increase the rate of reaction
Catalyst decrease the rate of reaction
Catalyst increase the activation energy needed to start a reaction
Catalyst decrease the activation energy needed to start a reaction
They are used up in the reaction
They are not used up in the reaction
Catalyst are very specific
Catalyst are not very specific
Catalyst increase the rate of reaction
Catalyst decrease the activation energy needed to start a reaction
They are not used up in the reaction
Catalyst are not very specific
Explanation:
From the basic chemistry it is known Catalysts are substance that accelerates the rate of reaction without altering the nature of reaction.
Catalysts decreases the energy required for activation, in order to make collisions quicker.
Then, Catalyst just alters the rate of reaction alone and doesn't takes part in the chemical reaction.
Some catalysts are specific. But in general most of the catalysts are not specific in nature.
List one way you can conserve water
Answer:
Shorter showers
Explanation:
A 5 to 10 minute shower will only take about 10 or 20 gallons of water. Or you could take a bath and not fill the bathtub up very much.
It's completely up to you which one you chose to use. Many people take 30 to 60 minute showers. Based on that math, that could take up to 120 gallons of water.
That shows that simply shortening your shower time, you will save gallons of water!
~CaityConcerto
You may remember that fresh water is the only type of water humans and animals can drink. For this reason, it is essential to life. What percentage of all water on Earth is fresh? options: 25% 75% 3% 90%.....
Answer:
3%
Explanation:
We have heard about the clean water crisis, but how can that happen if earth mostly covered in water? Even though 70% of the earth is covered in water, most of those water is at ocean and has a high concentration of salt. We can't drink those water because the salt will take more water from our bodies. Freshwater only makes up about 2.5-3% water bodies while the ocean makes up 97% of the rest. Out of 3% freshwater, we have, only 1% of them that easily accessible.