All categories

3 years ago

"Conservation of energy" refers to the fact that _____.

Chemistry

1 answer:

Agata [3.3K]3 years ago

8 0

Answer: Option (b) is the correct answer.

Explanation:

According to the law of conservation of energy, it is known that energy can neither be created nor it can be destroyed.

But energy can be changed from one form to another.

Whereas entropy is the degree of randomness present within the molecules of a substance or object.

For example, gas molecules are able to move rapidly so, they have more entropy as compared to solid and liquid substances.

According to second law of thermodynamics, entropy of the system is always increasing.

Thus, we can conclude that "Conservation of energy" refers to the fact that energy cannot be created or destroyed but can be converted from one form to another.

You might be interested in

Find the pH of a solution whose H concentration is 0.7 x 10-3.

dexar [7]

Answer: pH = 3.15

Explanation: Solved in the attached picture.

6 0

3 years ago

People take antacids, such as milk of magnesia, to reduce the discomfort of acid stomach or heartburn. The recommended dose of m

Llana [10]

Answer:

$V_{HCl}=0.208L=208mL$

Explanation:

Hello,

In this case, since the chemical reaction is:

$2HCl+Mg(OH)_2\rightarrow MgCl_2+2H_2O$

We can see that hydrochloric acid and magnesium hydroxide are in a 2:1 mole ratio, which means that the neutralization point, we can write:

$n_{HCl}=2*n_{Mg(OH)_2}$

In such a way, the moles of magnesium hydroxide (molar mass 58.3 g/mol) in 500 mg are:

$n_{Mg(OH)_2}=500mg*\frac{1g}{1000mg}*\frac{1mol}{58.3g} =0.00858mol$

Next, since the pH of hydrochloric acid is 1.25, the concentration of H⁺ as well as the acid (strong acid) is:

$[H^+]=[HCl]=10^{-pH}=10^{-1.25}=0.0562M$

Then, since the concentration and the volume define the moles, we can write:

$[HCl]*V_{HCl}=2*n_{Mg(OH)_2}$

Therefore, the neutralized volume turns out:

$V_{HCl}=\frac{2*0.00858mol}{0.0562\frac{mol}{L} }\\ \\V_{HCl}=0.208L=208mL$

Best regards.

3 0

3 years ago

All the elements of a family in the periodic table have what feature in common?a)they all have similar chemical properties.b)the

Vadim26 [7]

<span>Answer: D. They all have the same number of electrons in the electron cloud</span>

5 0

3 years ago

Read 2 more answers

In an experiment, 3.25 g of NH3 are allowed to react with 3.50 g of O2. 4NH3 + 5O2 > 4NO + 6H2O a. Which reactant is the limi

cluponka [151]

Answer:

2.61 g of NO will be formed

The limiting reagent is the O₂

Explanation:

The reaction is:

4NH₃ + 5O₂ → 4NO + 6H₂O

We convert the mass of the reactants to moles:

3.25g / 17 g/mol = 0.191 moles of NH₃

3.50g / 32 g/mol =0.109 moles of O₂

Let's determine the limiting reactant by stoichiometry:

4 moles of ammonia react with 5 moles of oxygen

Then, 0.191 moles of ammonia will react with (0.191 . 5) / 4 = 0.238 moles of oxygen. We only have 0.109 moles of O₂ and we need 0.238, so as the oxygen is not enough, this is the limiting reagent

Ratio with NO is 5:4

5 moles of oxygen produce 4 moles of NO

0.109 moles will produce (0.109 . 4)/ 5 = 0.0872 moles of NO

We convert the moles to mass, to get the answer

0.0872 mol . 30g / 1 mol = 2.61 g

7 0

3 years ago

Table Salt or NaCl is composed of sodium and chlorine. While the individual elements of sodium and chlorine are very reactive, t

Deffense [45]

Answer:

Chlorine is more likely to steal a valence electron from sodium.

Explanation:

Sodium is number 11 on the periodic table with one valence electron. Belonging to the first group, it's one of the alkali metal, which are known to be highly reactive. Chlorine is number 17 with seven valence electrons, and it's in the second-to-last group of halogens--also very reactive.

Considering that elements with one valence electron are just about 100% likely to give up electrons to reach a stable state, sodium would be the element that is more likely to lose its valence electron to chlorine. In other words, chlorine would be the electron thief.

5 0

3 years ago