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3 years ago

Identify a reason that chemical reactions release energy during the reaction process.

Chemistry

2 answers:

Bess [88]3 years ago

5 0

Answer:

option b

Explanation:

When the energy is released the process is called exothermic reaction. This happens when the bonds are broken in the reactants and the system release energy.

Usimov [2.4K]3 years ago

5 0

Answer:

a. forming bonds

Explanation:

The energy required to break a bond is endothermic that is energy is absorbed to break a bond.

The energy is released in the formation of a bond that is energy is released when a bond is formed.

The formula to find the ∆H of the reaction is

∆H (reaction) = ∆H (bonds Broken) - ∆H (bonds formed)

For example

$N_2+3H_2< >2NH_3$

$N_2$ contains one N≡N triple bond (Bond breaking 946 KJ per mol)

$H_2$ contains a single H-H bond (bond breaking 436 KJ per mol)

$NH_3$ contains 3, N - H single bonds(389 KJ per mol)

So ∆H (bonds broken) = 946 + (3 × 436) = 2254KJ

∆H (Bonds formed ) = (2 × 3 × 389) = 2334KJ

∆H (reaction) = 2254 KJ - 2334 KJ

= - 80KJ and the reaction is Exothermic

In this example we see energy required to break the bond is lesser than energy released in forming the bond.

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Which shell would be complete with 10 electrons?

nlexa [21]

Answer:

The answer to your question is letter d

Explanation:

If we remember there is a limit of electrons that can be place in a sublevel

Sublevel s only accept 2 electrons

Sublevel p only accept 6 electrons

Sublevel d only accept 10 electrons

Sublevel f only accept 14 electrons

This is in agreement wth the levels of energy, that only accept a determine number of electrons

Level Sublevel # of electrons

1 s 2

2 s and p 8 (2 + 6)

3 s, p and d 18 (2+6+10)

4 s, p, d, f 32 (2+6+10+14)

5 s, p, d,f 32 (2+6+10+14)

6 s, p, d 18 (2+6+10)

7 s, p 8 (2+6)

3 0

4 years ago

How many moles of sodium atoms do you have if you have 5.60 ~

Papessa [141]

Answer:

0.93 mol

Explanation:

Given data:

Number of moles of Na atom = ?

Number of atoms = 5.60× 10²³

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

5.60× 10²³ atoms × 1 mol / 6.022 × 10²³ atoms

0.93 mol

3 0

4 years ago

What is the volume at STP of 2.66 moles of methane gas

sineoko [7]

1 mole --------- 22.4 ( at STP )
2.66 moles ---- ?

V = 2. 66 * 22.4 / 1

V = 59.584 / 1

V = 59.584 L

hope this helps!

6 0

4 years ago

Which best explains why the total mass of the product(s) would be less than the

Elena-2011 [213]

The law of conservation of mass applies to all chemical reaction, so this means that there was equal mass before and after the reaction. However, if the mass has decreased, then it means there has been a loss of substance. The most common cause of this is the liberation of gases from a chemical reaction mixture, the mass of which is not measured by the scale.

6 0

3 years ago

Read 2 more answers

N2+3H2---> 2NH3

irakobra [83]

Hello!

A) How many grams of hydrogen are necessary to react completely with 50.0g of nitrogen in the above reaction?

The balanced chemical reaction is the following one:

N₂(g) + 3H₂(g) → 2NH₃(g)

To calculate the amount of hydrogen necessary we will use the following conversion factor to go from grams of nitrogen to grams of hydrogen:

$50 gN_2* \frac{1 mol N_2}{28,013 g N_2}* \frac{3 moles H_2}{1 mol N_2}* \frac{2,016 g H_2}{1 mol H_2}=10,7950 g H_2$

So, 10,7950 grams of H₂ are required to react with 50 g of nitrogen

B) How many grams of ammonia are produced in the reaction from the previous problem?

The balanced chemical reaction again is the following one:

N₂ + 3H₂ → 2NH₃

To calculate the amount of ammonia produced we will use the following conversion factor to go from grams of nitrogen to grams of ammonia:

$50 gN_2* \frac{1 mol N_2}{28,013 g N_2}* \frac{2 moles NH_3}{1 mol N_2}* \frac{17,031 g NH_3}{1 mol NH_3}=60,7968 g NH_3$

So, 60,7968 grams of NH₃ are produced from 50 g of nitrogen

C) How many grams of silver chloride are produced from 5.0g of silver nitrate reacting with an excess of barium chloride?

The balanced chemical equation for the reaction is the following one:

2AgNO₃ + BaCl₂ → 2AgCl + Ba(NO₃)₂

To calculate the mass of Silver Chloride produced we will use the following conversion factor to go from grams of Silver Nitrate to grams of Silver Chloride:

$5 g AgNO_3* \frac{1 mol AgNO_3}{169,87 g AgNO_3}* \frac{2 moles AgCl}{2 moles AgNO_3}* \frac{143,32 g AgCl}{1 mol AgCl}=4,2185 g AgCl$

So, 4,219 g of AgCl are produced from the reaction of 5 g of AgNO₃

D) How much barium chloride is necessary to react with the silver nitrate in the previous problem?

The balanced chemical equation for the reaction is the following one:

2AgNO₃ + BaCl₂ → 2AgCl + Ba(NO₃)₂

To calculate the mass of Barium Chloride necessary we will use the following conversion factor to go from grams of Silver Nitrate to grams of Barium Chloride:

$5 g AgNO_3* \frac{1 mol AgNO_3}{169,87 g AgNO_3}* \frac{1 mol BaCl_2}{2 moles AgNO_3}* \frac{208,23 g BaCl_2}{1 mol BaCl_2}=3,08 g BaCl_2$

So, 3,08 g of BaCl₂ are produced from the reaction of 5 g of AgNO₃

Have a nice day!

4 0

3 years ago