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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

what is the difference between a chemical bonds formed in the molecules of 02 and the chemical bonds formed in crystals of a NaC

Jobisdone [24]

Answer:

O2 is a covalent substance while NaCl is an ionic substance

Explanation:

In O2 molecule, the bond is between 2 oxygen atoms which are non - metals. Thus, this is a covalent bond since it involves 2 non metals.

Whereas, for the NaCl molecule, the bond is between a metal sodium (Na) and a non metal Chloride(Cl) and thus we can say this is an ionic bond.

Thus the difference is that O2 is a covalent substance while NaCl is an ionic substance.

8 0

2 years ago

Zinc metal reacts with hydrochloric acid to produce zinc(II) chloride and hydrogen gas. How many liters of hydrogen gas will be

AleksAgata [21]

Answer:

0.120 L of hydrogen gas will be produced

Explanation:

Step 1: Data given

Mass of zinc = 10.0 grams

Volume of hydrochloric acid = 23.8 mL

Molarity of hydrochloric acid = 0.45 M

Molar mass of zinc =65.38 g/mol

Step 2: The balanced equation

Zn + 2HCl → ZnCl2 + H2

Step 3: Calculate moles Zinc

Moles Zn = mass Zn / molar mass Zn

Moles Zn = 10.0 grams / 65.38 g/mol

Moles Zn = 0.153 moles

Step 4: Calculate moles HCl

Moles HCl = molarity * volume

Moles HCl = 0.45 M * 0.0238 L

Moles HCl = 0.01071 moles

Step 5: Calculate limiting reactant

For 1 mol Zn, we need 2 moles HCl to produce 1 mol ZnCl2 and 1 mol H2

HCl is the limiting reactant. It will completely be consumed (0.01071 moles)

Zn is in excess. There will react 0.01071/2 = 0.005355 moles

There will remain 0.153 - 0.005355 = 0.147645 moles

Step 6: Calculate moles H2

For 1 mol Zn, we need 2 moles HCl to produce 1 mol ZnCl2 and 1 mol H2

For 0.01071 moles HCl we'll have 0.005355 moles H2

Step 7: Calculate volume H2

1 mol at STP = 22.4 L

0.005355 moles = 22.4 * 0.005355 = 0.120 L = 120 mL

0.120 L of hydrogen gas will be produced

4 0

3 years ago

6. Consider the reaction: CzHo (g) + 02 (8) - 4 CO2(g) + 6H2O (1)

deff fn [24]

Answer:

1120 gm

Explanation:

6. Consider the reaction: CzHo (g) + 02 (8) - 4 CO2(g) + 6H2O (1)

(a) Balance the equation.

(b) How many grams of oxygen are required to react with 10 moles of ethane for a complete

combustion reaction?

FIRST, CORRECT THE EQUATION THEN BALANCE

2C2H6(G) + 7O2------------> 4CO2 + 6H2O

so for 10 moles of ethane, we need

7 X 5 = 35 MOLES O2

=35 MOLES O2

O2 HAS A MOLAR MASS OF 2X16 = 32 gm

35 MOLES OF O2 HAS A MASS OF 35 X 32 =1120 gm

6 0

3 years ago

The rate constant for a certain reaction is measured at two different temperatures:

Talja [164]

Answer: The activation energy Ea for this reaction is 22689.8 J/mol

Explanation:

According to Arrhenius equation with change in temperature, the formula is as follows.

$ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}]$

$k_1$ = rate constant at temperature $T_1$ = $2.3\times 10^8$

$k_2$ = rate constant at temperature $T_2$ = $4.8\times 10^8$

$E_a$ = activation energy = ?

R= gas constant = 8.314 J/kmol

$T_1$ = temperature = $280.0^0C=(273+280)=553K$

$T_2$ = temperature = $376.0^0C=(273+376)=649K$

Putting in the values ::

$ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}]$

$E_a=22689.8J/mol$

The activation energy Ea for this reaction is 22689.8 J/mol

3 0

3 years ago

How many electrons will be in the valence of non- H atoms when they make covalent bonds?

NNADVOKAT [17]

Answer:

Please one time click here

Mark brainliest

8 0

2 years ago