By studying fossils, scientists have learned that A. Both animals and plants have changed over time. B. Plants have changed over time, but animals have not. C. Animals have changed over time, but plants have not. D. Neither animals nor plants have changed over time

Answers

Answer 1

Answer:A. Both animals and plants have changed over time.

Explanation:

Because plants and animals go through adaptations.

Answer 2

Answer: A. Both animals and plants have changed over time.

Explanation: study island


Related Questions

Which solution below has the highest concentration of hydroxide ions?a. pH= 3.21b. pH= 7.00c. pH= 7.93d. pH= 12.59e. pH= 9.82

Answers

Answer:

The solution that has the highest concentration of hydroxide ions is d. pH = 12.59.

Explanation:

You can solve this question using just some chemical facts:

pH is a measure of acidity or alkalinity: the higher the pH the lower the acidity and the higher the alkalinity.The higher the concentration of hydroxide ions the lower the acidity or the higher the alkalinity of the solution, this is the higher the pH.

Hence, since you are asked to state the solution with the highest concentration of hydroxide ions, you just pick the highest pH. This is the option d, pH = 12.59.

These mathematical relations are used to find the exact concentrations of hydroxide ions:

pH + pOH = 14 ⇒ pOH = 14 - pH

pOH = - log [OH⁻] ⇒ [tex][OH^-]=10^{-pOH}[/tex]

Then, you can follow these calculations:

Solution    pH        pOH                            [OH⁻]

a.               3.21       14 - 3.21 = 10.79        antilogarithm of 10.79 = 1.6 × 10⁻¹¹

b.               7.00      14 - 7.00 = 7.00        antilogarithm of 7.00 = 10⁻⁷

c.                7.93      14 - 7.93 = 6.07        antilogarithm of 6.07 = 8.5 × 10⁻⁷

d.               12.59     14 - 12.59 = 1.41        antilogarithm of 1.41 = 0.039

e.               9.82      14 - 9.82 = 4.18        antilogarithm of 4.18 = 6.6 × 10⁻⁵

From which you see that the highest concentration of hydroxide ions is for pH = 12.59.

The pH with the highest hydroxide ion is 12.59

What is pH?

pH is the degree of acidity or alkalinity in a solution.

The lower the pH, the higher the acidity.The higher the pH the higher the basicity.

When the concentration is higher, it has more hydroxide ion.

Therefore, The pH with the highest hydroxide ion is 12.59 because the higher the pH the higher the concentration of the hydroxide ion.

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What happens with the atomic numbers in nuclear equations?

Increase

Decrease

Conserved

Nothing

Answers

Answer:

Conserved

Explanation:

In balancing nuclear reaction equations, there is conservation of mass numbers and atomic numbers, i.e the sum of the mass number on the product side must be equal to the sum of mass numbers on the reactant side.

Also, the sum of the atomic numbers on the product side must be equal to the sum of the atomic numbers on the reactant side.

Note: A nuclear reaction is a process in which a nucleus reacts with an elementary particle.

what did Rutherford observe that surprised him?

A. most of the alpha particles shot at the gold foil bounced back.

B. most of the alpha particles shot at the gold foil went straight through the foil.

c. none of the alpha particles went through the gold foil.

D. all of the alpha particles went straight through the gold foil.

Answers

Answer:

Some of the Alpha particles shot at the gold foil bounced back.

Explanation:

Rutherford observed that most of the alpha particles shot at the gold foil went straight through the foil.

Why Rutherford was surprised?

The alpha-particle scattering experiment is an important experiment that led Rutherford to give an accurate description of the distribution of positive and negative charges within the atom. Alpha particle source is placed in the lead cavity. The alpha particles emitted by the source are collimated into a narrow beam with the help of lead and slit.

The observations of Rutherford’s Alpha Scattering Experiment are: First, he observe that most of the α-particles that are bombarded towards the gold sheet pass away the foil without any deflection, and hence it shows most of the space is empty.

The correct answer is option B.

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Place the following in order of decreasing molar entropy at 298 k. H2 cl2 f2

Answers

cl2>F2>H2

we can do this by molar mass

Hydrogen - 1

clorine - 35 x2 = 70

flourine- 18 x 2 = 36

flourine - 18

Molar mass has a direct relationship with entropy. The order of decreasing molar entropy at 298K is F[tex]_2[/tex]> Cl[tex]_2[/tex] > H[tex]_2[/tex].

What is entropy?

Entropy is a measurable physical characteristic and a scientific notion that is frequently connected to a condition of disorder, unpredictability, or uncertainty. It has several applications in physics and chemistry, as well as in biological systems as well as how they relate to life.

The phrase and the idea are employed in many different contexts, including information theory and classical thermodynamics. Molar mass has a direct relationship with entropy. The order of decreasing molar entropy at 298K is F[tex]_2[/tex]> Cl[tex]_2[/tex] > H[tex]_2[/tex].

Therefore, the order of decreasing molar entropy at 298K is F[tex]_2[/tex]> Cl[tex]_2[/tex] > H.

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Why is the answer C for this problem?

Answers

Answer:

[tex]\boxed{\text{(C) X}$_{3}$P$_{2}}[/tex]

Explanation:

Step 1. Identify the Group that contains X

We look at the consecutive ionization energies and hunt for a big jump between them

[tex]\begin{array}{crc}n & IE_{n} & IE_{n} - IE_{n-1}\\1 & 730 & \\2 & 1450 & 720\\3 & 7700 & 6250\\4 & 10500 & 2800\\\end{array}[/tex]

We see a big jump between n = 2 and n = 3. This indicates that X has two valence electrons.

We can easily remove two electrons, but the third electron requires much more energy. That electron must be in the stable, filled, inner core.

So, X is in Group 2 and P is in Group 15.

Step 2. Identify the Compound

X can lose two valence electrons to reach a stable octet, and P can do the same by gaining three electrons.

We must have 3 X atoms for every 2 P atoms.

The formula of the compound is [tex]\boxed{\text{X}$_{3}$P$_{2}}$}[/tex].

During a combustion reaction, 8.00 grams of oxygen reacted with 4.00 grams of CH4.

What is the amount of the leftover reactant?

2.78 grams of oxygen
2.10 grams of oxygen
1.99 grams of methane
1.78 grams of methane

Answers

Answer:

1.99 grams of methane

Explanation:

A combustion reaction always produces the product carbon dioxide and water. So the chemical equation for this reaction would be:

CH₄ + O₂ → CO₂ + H₂O

To answer this question, you need to first determine which is the excess reactant. First step is to balance the equation:

CH₄ + 2O₂ → CO₂ + 2H₂O

Next we get the number of moles of each reactant we actually have:

8.00 g of O₂ = ? moles of O₂

You can get the number of moles, by first computing how many grams of the molecule is present in 1 mole.

O = 15.999g/mole. Since there are 2 oxygens in one mole of O₂, all you need to do is add up the atomic mass of 2 oxygens. You will get:

O₂= 31.998 g/mole

You can use this then to determine how many moles of O₂ there are in 8.00g.

[tex]8.00g\times\dfrac{1mole}{31.998g}=0.250moles[/tex]

So there are 0.250 moles of O₂ in 8.00 g of O₂.

We do the same for CH₄

4.00g of CH₄=? moles of CH₄

            C           H₄

CH₄= 12.011 + 1.008(4) = 16.043 g/mole

[tex]4.00g\times\dfrac{1mole}{16.043g}=0.249moles[/tex]

So let's sum up our new given. We now have:

0.250 moles of O₂

0.249 moles of CH₄

Next we look at the molar ratio of reactants to produce products:

CH₄ + 2O₂ → CO₂ + 2H₂O

According to this equation we can assume the following:

We need 1 mole of CH₄ for every 2 moles of O₂ in this reaction. Using what we have, we will see how much of reactant of the other reactant we need to use up the other.

[tex]0.25molesofO_{2}\times\dfrac{1moleofCH_{4}}{2molesofO_{2}}=0.125molesofCH_{4}\\\\0.249molesofCH_{4}\times\dfrac{2molesofO_{2}}{1moleofCH_{4}}=0.498molesofO_{2}[/tex]

Compare the results with what we have:

What we have                   What we need

0.250 moles of O₂   <     0.498 moles of O₂

0.249 moles of CH₄ >     0.125 moles of CH₄

This means that since we have less O₂ that what we need to use up CH₄, then O₂ is the limiting reactant and CH₄ is the excess.

To compute how much we have in excess, we use the number of moles produced when we use up limiting reactant which we did earlier and convert it into grams to determine how much in grams we used up.

Earlier we solved that we need 0.125 moles of CH₄ to use up all the O₂. Now convert that value into grams:

[tex]0.125molesofCH_{4}\times\dfrac{16.043gofCH_{4}}{1moleofCH_{4}}=2.005g of CH_{4}[/tex]

This means that 2.005g of CH₄ will be used up.

Subtract that from the CH₄ we already have:

4.00 g - 2.005 g =1.99 g of CH₄

If you are given a chemical equation and specific amounts for each reactant in grams, how would you determine how much product can possibly be made? if you are given a chemical equation and specific amounts for each reactant in grams, how would you determine how much product can possibly be made? 1. convert each reactant into moles of the product. 2. determine which reactant is the limiting reactant. 3. convert the moles of product, from the limiting reactant, to grams. 1. determine which reactant is the limiting reactant. 2. convert each reactant into moles of the product. 3. convert the moles of product, from the limiting reactant, to grams. 1. determine which reactant is the limiting reactant. 2. using conversion factor, convert grams of the limiting reactant to grams of the product.

Answers

1. Find the mole of each reactant present and determine the limiting reactant 2. determine the mole of product produced through the mole ratio of the equation 3. convert to grams if the 'amount' refers to grams

Oxides of nitrogen result from a combination of nitrogen and A. hydrogen. B. carbon. C. oxygen. D. argon.

Answers

When something is oxidized it means that oxygen is added to it. Therefore the answer is C. Oxygen!

Hope this helped!

Oxides of nitrogen result from a combination of nitrogen and oxygen. Hence, the correct answer is C. oxygen.

Oxides of nitrogen, commonly known as nitrogen oxides or NOx, are usually formed from a combination of nitrogen and oxygen. Specifically, they refer to compounds that basically contain nitrogen and oxygen atoms, such as nitrogen monoxide (NO), nitrogen dioxide (NO₂), and nitrogen trioxide (N₂O₃).

Generally, these oxides of nitrogen are often produced during high-temperature combustion processes, such as those occurring in vehicle engines, power plants, and industrial processes. The primary source of oxygen for the formation of nitrogen oxides is atmospheric oxygen (O₂).

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Name two things in the lab that are for safety

Answers

Answer:

Safety goggles and chemical fume hoods

Explanation:

Fill in the missing mass number and atomic number for each of these particles or types of radiation.



alpha (?) He



beta (?) e



gamma y



neutron n

Answers

Answer:

Particle /                          mass number                atomic number

type of radiation

alpha / ⁴₂ He                              4                                     2

beta / e⁰                                     0                                   - 1

gamma / γ                                  0                                     0

neutron / n                                 1                                      0

Explanation:

These are the basic types of radiation: alpha (α), beta (β),  gamma (γ), and neutrons (n).

The radiation is emitted by unstable nuclei when undergo radiactive decay or by nuclei that are shooted by other particles.

Alpha radiation (⁴₂ He):

They are nuclei of helium-4 atoms: 2 protons and 2 neutrons.

Hence, the atomic number, which is the number of protons,  of these particles, is 2; and the mass number, which is the sum of protons and neutrons, is 2 + 2 = 4.

The symbol of this radiation is ⁴₂ He, where the superscript to the left of the chemical symbol is the mass number and the subscript to the left of the chemical symbol is the atomic number.

Beta (⁰₋ ₁ e)

These are electrons emiited from an unstable nucleus. The symbols used for this particle are either ⁰₋ ₁β or ⁰₋ ₁e.

The superscript 0 indicates that the relative mass of this particle is practically zero and the subscript -1 tells that the emission of electrons increases the atomic number of the nucleus that emits it.

Gamma (⁰₀γ)

The gamma rays are electromagnetic radiation of high (the highest) energy.

The both superscript and subscript are zero, meaning that this radiation does not change either the mass or atomic numbers of the nucleus.

Neutron (¹₀n):

Neutrons are also emiited from the nucleus and so they may be considered a radiation.

The atomic number of neutrons is 0 (since it does not have protons) and its mass number is 1.

Radioactive rays are divided into three, namely alpha rays, beta rays, and gamma rays.  

Check the picture below!

Further Explanation

Types of Radioactive Rays

Based on the constituent particles, radioactive rays are divided into three, namely alpha rays, beta rays, and gamma rays.

Alfa ray (α ray)

Alpha rays are rays emitted by radioactive elements. This ray was discovered simultaneously with the discovery of the phenomenon of radioactivity, which is the decay of the nucleus which takes place spontaneously, uncontrolled, and produces radiation. Alpha rays consist of two protons and two neutrons. The following are the nature of alpha rays.

Beta Rays (β Rays)

Beta rays are high-energy electrons that originate from the nucleus. Here are some of the nature of beta rays.

Has a smaller ionization power than alpha rays. Has a greater penetrating power than alpha rays. Can be deflected by electric or magnetic fields.

Gamma Rays (Rays ˠ)

Gamma rays are radiation from electromagnetic waves that emanate from very high energy nuclei that have no mass or charge. Gamma rays also emit when a core emits alpha rays and beta rays. Gamma-ray decay does not cause changes in atomic number or atomic mass.

Gamma rays have the following natural properties:

Gamma rays do not have maximum coverage in the air, the farther away from the source the intensity is smaller. Has the weakest ionization power. Has the greatest penetrating power. Do not turn in the electric and magnetic fields.

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Class: High School

Subject: Chemistry

Keyword: Alpha, Beta, Gamma

What happens to the atoms that make up ethanol as it burns?

Answers

the burning of ethanon is an exothermic reaction.

exothermic = releases heat.

knowing this, we can see that the atoms are released into the atmosphere, it then reacts with oxygen, producing cardon dioxide, water, and heat.

The activation energy of a certain reaction is 40.1 kj/mol . at 26 ∘c , the rate constant is 0.0160s−1. at what temperature in degrees celsius would this reaction go twice as fast? express your answer with the appropriate units. view available hint(s)

Answers

Answer:

[tex]\boxed{\text{39 }^{\circ}\text{C}}[/tex]

Explanation:

We can use the Arrhenius equation:

[tex]\ln(\frac{k_2 }{k_1}) = \frac{E_{a} }{R}(\frac{1}{T_1} - \frac{1 }{T_2 })[/tex]

Data:

Eₐ = 40.1 kJ·mol⁻¹

k₁ = 0.0160 s⁻¹;              k₂ = 0.0320 s⁻¹

T₁ = 26 °C = 299.15 K; T₂ = ?  

Calculations:

[tex]\ln(\frac{0.0320}{0.0160}) = \frac{40 100 }{8.314}(\frac{ 1}{299.15}} - \frac{1 }{T_{2} })\\\\\ln2 = 4823(\frac{ 1}{299.15}} - \frac{1}{T_{2} }) \\\\\ln2 - 16.12 = -\frac{4823}{T_{2} }\\\\-15.43 = -\frac{4823}{T_{2} }\\\\T_{2} = \frac{4823}{15.43} =\textbf{312.6 K}[/tex]

T₂ = 312.6 K = 39 °C

The reaction will go twice as fast at [tex]\boxed{\text{39 }^{\circ}\text{C}}[/tex].

The temperature at which the reaction would go twice as fast, given an activation energy of 40.1 kJ/mol and an initial rate constant of 0.0160 s⁻¹ at 26 °C, is approximately 39.4 °C.

Solution

We can use the Arrhenius equation to solve this problem:

k = A * e^(-Ea / (R * T))

where:

k is the rate constant,Ea is the activation energy (40.1 kJ/mol),R is the gas constant (8.314 J/mol·K),T is the temperature in Kelvin,A is the frequency factor (which cancels out when comparing two temperatures).

Given that the rate constant at 26 °C (299 K) is 0.0160 s⁻¹ and we need to find the temperature where the rate constant doubles (0.0320 s⁻¹), we can use the two-point form of the Arrhenius equation:

ln(k₂ / k₁) = -Ea / R * (1/T₂ - 1/T₁)

where:

k₁ = 0.0160 s⁻¹, T₁ = 299 Kk₂ = 0.0320 s⁻¹and we need to find T₂.

Rearrange the equation to solve for T₂:

ln(0.0320 / 0.0160) = -40,100 J/mol / 8.314 J/mol·K * (1/T₂ - 1/299 K)

Solve for the ratio of rate constants:

ln(2) = 40,100 / 8.314 * (1/299 K - 1/T₂)
0.693 = 4,822.6 * (1/299 K - 1/T₂)
(1/299 K - 1/T₂) = 0.693 / 4,822.6
(1/299 K - 1/T₂) ≈ 0.0001437

Solve for 1/T₂:

1/T₂ = 1/299 K - 0.0001437
1/T₂ ≈ 0.003346 - 0.0001437
1/T₂ ≈ 0.0032023
T₂ ≈ 312.4 K

Convert T₂ to degrees Celsius:

T₂ - 273 ≈ 39.4 °C

Therefore, the temperature at which the reaction would go twice as fast is approximately 39.4 °C.

A nascar racecar can attain speeds of over 225 miles/hour on super speedways. How fast is this in km/hr

Answers

It is 362.102 km/hr

Answer:

The correct answer is [tex]362.32 \frac{km}{hour}[/tex]

Explanation:

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other, the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:

A ⇒ B

C ⇒ x

So [tex]x=\frac{C*B}{A}[/tex]

The direct rule of three is the rule applied in this case where there is a change of units. To perform this conversion of units, you must first know that 1km = 0.621 miles. So, if 1 km is 0.621 miles, how many kilometers equals 225 miles?

[tex]x kilometers=\frac{225 miles*1 km}{0.621 miles}[/tex]

[tex]x kilometers=362.32 kilometers[/tex]

So, finally,

[tex]225 \frac{miles}{hour} =362.32 \frac{miles}{hour}[/tex]

Which chemical reaction would result in the greatest release of energy?

a.adp + p --> atp

b.atp + oxygen --> adp + p

c.pyruvic acid + nadh --> lactic acid + nad+

d.carbon dioxide + water --> glucose + oxygen?

Answers

The answer is B.

ATP + Oxygen ---> ADP + P

Calculate the pka of hypochlorous acid. The ph of a 0.015 m solution of hypochlorous acid has a ph of 4.64.

Answers

Answer:

pKa = 7.46

Explanation:

1) Data:

a) Hypochlorous acid = HClO

b) [HClO} = 0.015

c) pH = 4.64

d) pKa = ?

2) Strategy:

With the pH calculate [H₃O⁺], then use the equilibrium equation to calculate the equilibrium constant, Ka, and finally calculate pKa from the definition.

3) Solution:

a) pH

pH = - log [H₃O⁺]

4.64 = - log [H₃O⁺]

[tex][H_3O^+]= 10^{-4.64} = 2.29.10^{-5}[/tex]

b) Equilibrium equation: HClO (aq) ⇄ ClO⁻ (aq) + H₃O⁺ (aq)

c) Equilibrium constant: Ka =  [ClO⁻] [H₃O⁺] / [HClO]

d) From the stoichiometry: [CLO⁻] = [H₃O⁺] = 2.29 × 10 ⁻⁵ M

e) By substitution: Ka = (2.29 × 10 ⁻⁵ M)² / 0.015M = 3.50 × 10⁻⁸ M

f) By definition: pKa = - log Ka = - log (3.50 × 10 ⁻⁸) = 7.46

Which statements are true of the reaction below? 2na(s) + cl2(g) 2nacl(s) Check all that apply. A - NaCl is a product B - Na(s) is a product C - A chemical reaction does not happen D - Cl2 is a gas

Answers

Answer:

A - NaCl is a product

D - Cl2 is a gas

Explanation:

Based on the chemical reaction;

2Na(s) + Cl2(g) → 2NaCl2

Sodium metal reacts with chlorine gas to form sodium chloride. Sodium is in solid state, chlorine is in gaseous state and Sodium chloride is in solid state.In the chemical reaction, sodium and chlorine are reactants while sodium chloride is the product.Additionally the chemical reaction above is balanced so as to obey the law of conservation of mass.
Final answer:

The true statements for the reaction 2Na(s) + Cl2(g) → 2NaCl(s) are that NaCl is a product and Cl2 is a gas. Sodium (Na) is a reactant, not a product, and a chemical reaction does occur in this equation.

Explanation:

The reaction given is 2Na (s) + Cl2(g) → 2NaCl (s). This chemical equation is balanced, indicating that the same number and types of atoms appear on both sides of the equation. The equation demonstrates the reaction of solid sodium (Na) with chlorine gas (Cl2) to form sodium chloride (NaCl), a solid.

For the statements provided:

NaCl is a product: This is true because NaCl appears on the right side of the arrow, indicating it is the result of the reaction.Na(s) is a product: This is false because Na appears on the left side of the arrow, meaning it is a reactant, not a product.A chemical reaction does not happen: This is false as the equation clearly shows a chemical reaction taking place.Cl2 is a gas: This is true as indicated by the (g) after Cl2, denoting it is in the gaseous state before the reaction.

Key Notes to Remember:

Chlorine is one of the seven elements that exist in nature as diatomic molecules, which include H2, N2, O2, Cl2, Br2, and I2—this is important for balancing chemical equations correctly.

What is the fraction of the hydrogen atom's volume that is occupied by the nucleus? the bohr radius is 0.529×10−10m?

Answers

The radius of an electron in the third shell of the hydrogen atom, according to the Bohr model, is calculated as 4.7628 x 10⁻¹⁰ meters.

To calculate the radius of an electron in the third shell (n=3) of the hydrogen atom according to the Bohr model of the hydrogen atom, you use the formula that relates the main quantum number (n) to the radius of the electron's orbit. The radius of an orbit (rn) in the Bohr model is given by the equation rn = n2 imes ao, where ao is the Bohr radius and equals 5.292  imes 10
11 m. For the third shell, n=3, so the calculation is r3 = 32  imes 5.292 imes 10-11 m = 9 imes 5.292 imes 10-11 m.

Therefore, the radius of an electron in the third shell is r3 = 47.628 imes 10-11 m = 4.7628 imes 10-10 m. Keep in mind that while this model provides insight, it has been refined by quantum mechanics.

write a balanced equation that describes the dissociation of chromium(III) nitrate in water

Answers

Final answer:

The balanced equation for the dissociation of chromium(III) nitrate in water is Cr(NO3)3 (s) → Cr3+ (aq) + 3 NO3- (aq), illustrating the separation into chromium(III) ions and nitrate ions.

Explanation:

The balanced equation that describes the dissociation of chromium(III) nitrate in water is as follows:

Cr(NO3)3 (s) → Cr3+ (aq) + 3 NO3− (aq)

When chromium(III) nitrate dissolves in water, it separates into chromium(III) ions and nitrate ions. Each formula unit of the solid compound yields one chromium(III) ion and three nitrate ions. The equation is balanced with respect to both mass and charge, fulfilling the law of conservation of mass and the principle of electroneutrality.

To describe the process, it is important to note that chromium(III) nitrate is a salt, and like most salts, it dissociates completely in water to give its constituent ions.

given the equation 2Na+Cl2 ​ →2NaCl How many moles of NaCl will be produced from 59.0 grams of Na, assuming Cl is available in excess?

Answers

I would use dimensional analysis for this problem. You would start with the given amount of Na which is 59.0g. You are trying to find the moles of NaCl.

(59.0g Na)*(1 mol Na)/(22.99 g Na)*(2 mol NaCl)/(2 mol Na)=

2.57 mol NaCl

The units will cancel out until you are left with moles of NaCl. The answer has the correct number of significant figures (3 sig figs).

Answer: 2.56 moles

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} Na=\frac{59.0g}{23g/mol}=2.56moles[/tex]

[tex]2Na(s)+Cl(g)\rightarrow 2NaCl(s)[/tex]

Na is the limiting reagent as it limits the formation of product and chlorine is the excess reagent.

According to stoichiometry :

2 moles of Na produce = 2 moles of NaCl

Thus 2.56 moles of Na produce =[tex]\frac{2}{2}\times 2.56=2.56moles[/tex]  of NaCl

Thus 2.56 moles of NaCl are produced.

the pressure of a sample of helium in a 0.2 L container is 2.0atm. if the helium is compressed to a volume of 10.0 ml ,what would be the pressure of the gas?

Answers

Answer:

The pressure of the gas is 40atm

Explanation:

Given parameters:

P₁ = 2.0atm

V₁ = 0.2L

V₂ = 10.0mL = 10 x10⁻³L = 0.01L

P₂ =?

We apply Boyle's law to solve this kind of problem

Boyle's law states that "the volume of a fixed mass of a gas varies inversely as the pressure changes if the temperature is constant".

It is expressed as P₁V₁ = P₂V₂

Making P₂ the subject of the formula gives:

P₂ = P₁V₁/V₂

Inserting the values of the parameters:

P₂ = 2x0.2/0.01

P₂ = 40atm

The formula H2SO4 is representative of which of the following?A. an acid B. a catalyst C. an organic compound D. a base

Answers

Absolutely an acid ,because:

1)we it is sulfuric acid s molecular formula

2) in its shape H atom bonded with (O),not central atom

Answer:

A. An acid

Explanation:

Hello,

In inorganic chemistry, oxyacids are characterized by the presence of hydrogen, a nonmetal and oxygen as they are formed when an acid oxide (formed with a  nonmetal and oxygen) reacts with water. In this case, as the molecule has hydrogen, sulfur and oxygen, such constituting atoms match with the definition of an oxyacid, that is why H₂SO₄ is an acid.

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Silver tarnishing is an example of what type of change?
Physical change
Chemical change
Alchemical change
Temperature change

Answers

Answer:

that a chemical change

Explanation:

because it changing properties

It’s Chemical change

The freezing point and the boiling point of water can be altered by a variety of techniques. Which of the following has little or no effect on the boiling point of water? A: Increasing the air pressure above the liquid B: Adding alcohol to the water C: Adding sodium chloride to the water D: Increasing the amount of water

Answers

Answer:

D: Increasing the amount of water.

Explanation:

Choice A: ­ increasing the pressure can force the liquid to stay a liquid  and affect the boiling point (decrease it).

Choice B and C: ­ both involve colligative properties, adding a solute to water will  increase the boiling point  of water.

Choice D: ­ just having more water does not change the boiling point of the water as this minimize the effect of any external factor.

So, the right choice is: D: Increasing the amount of water.

It is inappropriate to give a couple's shower.

True
False

Answers

The statement that a couples' shower is inappropriate is false. Couples' showers are a modern, inclusive celebration for both members of a couple and are deemed appropriate based on the couple's preference and cultural norms.

The assertion that it is inappropriate to give a couples' shower is false. A couples' shower is a modern take on traditional bridal showers, and is considered an appropriate event. It involves both members of the couple, regardless of gender, and allows guests who are close to both individuals to celebrate their union together. The appropriateness of a couples' shower is determined by the couple's preferences and the social norms of their community or culture.

Cu ag and au are all in what group number

Answers

Answer:

Cu, Ag, and Au are all in the group number 11

Explanation:

To answer this question you must look at your periodic table.

The elements in the periodic table are ordered in increasing order of atomic number and elements with similar chemical properties, due to the same number of valence eletrons, lay in the same column.

The column in the periodic table corresponds to the chemical group, and,  in the most modern version, is identified with a number 1 through 18.

The elments Cu (copper), Ag (silver), and Au (gold), all metals, are in the same group (column) number 11.

The elements in the columns 3 trough 12 are transition metals. The atomic numbers of thise elements, which let you to find them easily in your periodic table, are:

Cu: 29 (it is the first element in the group)Ag: 47 (it is directly below Cu)Au: 79 (79 ( it is directly below Ag)

Those elements, along with platinum are paladium, are the metals with the lowest reactivity, which is the reason why they are found in nature in its pure form (not combined with other elements).

Cu, Ag, and Au are all in Group 11 of the periodic table, known for having eleven valence electrons and being part of the d-block transition metals. They appear in various transition series (Cu in the first, Ag in the second, and Au in the third) and can form d10 coordination complexes.

The elements Cu (Copper), Ag (Silver), and Au (Gold) all belong to Group 11 of the periodic table. These metals are collectively known as the coinage metals and are characterized by having eleven valence electrons. They are part of the d-block elements, specifically included in the transition metals category. Copper is in the first transition series, silver is part of the second, and gold falls within the third. The properties of these metals, such as their high conductivities and malleability, make them highly valuable and extensively used in coins, jewelry, and electronics.

Moreover, when these elements form complexes with coordination number 2, as seen with d10 metal ions like Cut, Ag+, and Aut, they typically exhibit a linear L-M-L structure. Such configurations can be useful in various applications including the extraction of gold from its ores.

If the momentum of an electron were doubled, how would its wavelength change?

Answers

Answer:

If the momentum of an electron were doubled its wavelength would be shortened to half the original value.

Explanation:

The relation between the momentum and the wavelength of a particle is given by De Broglie's equation:

λ = h / p

Where, λ is the wavelength, h is Planck's constant, and p  is the momentum.

h = 6.63 × 10⁻³⁴ J.s

Therefore, as per De Broglie's equation, the momentum of an electron and its wavelength are inversely related, meaning that if the momentum of an electron were doubled its wavelength would be shortened to half the original value.

A solution of a base differs from a solution of an acid in that the solution of a base?A. is able to conduct electricity B. is able to cause an indicator color change C. has a great [H3O+] D. has a great [OH-]

Answers

Answer:

Option D. has a great [OH⁻]

Explanation:

1) Both acids and bases ionize in aqueous solutions so they are able to conduct electricity.

The ions, being charged particles, when flow through the solution are charge carriers, then they conduct electricity.

So, the option A does not state a difference between a solution of a base and a solution of an acid.

2) Both acids and bases are able to cause an indicator color change.

The usufulness of the indicators is that they are able to change of color when the pH changes either from acid to basic or from basic to acid. There are different indicators because none is suitable for the whole range of pH, but the statement B is not how solutions of base and acids differ.

3) The model of Arrhenius for acids and bases states that an acid is a substance that ionizes in water releasing H⁺ ions (this is equivalent to H₃O⁺) and a base is a substance that releases OH⁻ ions in water. Then, acids have a greater concentration of H₃O⁺ (so option C is not true for a solution of a base) and bases  have a greater concentraion of OH⁻, making the option D. true.

Answer:

D. Has a great [OH-]

Explanation:

Castle learning

What is the pH of a solution with a pOH of 10?

6

4

10

14

Answers

Answer:

= 4

Explanation:

The pH of a solution is given by;

pH = - log [H+] , while

pOH = - log [OH-]

But; pH + pOH = 14

Therefore;

pH = 14 - pOH

     = 14 - 10

     = 4

4 is the correct answer

Heat measures the average kinetic energy a substance's molecules.


TRUE


FALSE

Answers

Answer:

False this is like the definition of temperature

Explanation:

Predict which molecule will show a similar relationship between its heat of fusion and its heat of vaporization that water does.

A) C6H6

B) CH3CH2CH2CH2CH2COH6

C) NaCl

D) NH3

Answers

Specific heat capacity of a substance is the amount of heat required to raise the temperature by one degree Celsius of one gram of a substance. Therefore, the correct option is option A.

What is Enthalpy?

Enthalpy term is basically used in thermodynamics to show the overall energy that a matter have. Mathematically, Enthalpy is directly proportional to specific heat capacity of a substances.

Mathematically,

q = n ×ΔH

where

q = amount of heat

n = no of moles

ΔH = enthalpy

n = w / M.M

w = given mass

M.M = molar mass

A) C₆H₆

melting point =5.5° C

boiling point =80.1 ° C

Heat of fusion = 9.92 kJ/mol

Heat of vaporization =30.8kJ/mol

B) CH₃CH₂CH₂CH₂CH₂COH₆ is solid

C) NaCl is solid

D) NH₃

melting point = -77.73 °C

boiling point =  -33.34 °C

Therefore, the correct option is option A.

To know more about enthalpy, here:

brainly.com/question/24170335

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