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4 years ago

How do you know if a reaction is endothermic? 40 points!!!!!

2 answers:

6 0

The term endothermic process describes a process or reaction in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat.

stepladder [879]4 years ago

5 0

<span>A reaction is endothermic if, overall, energy is absorbed during the reaction. And it is usually exerted as heat! I hope I helped. And let me know if you need help with anything else. :)</span>

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Blast furnaces extra pure iron from the Iron(IIl)oxide in iron ore in a two step sequence. In the first step, carbon and oxygen

OLga [1]

Answer:

5.9 kg

Explanation:

We must work backwards from the second step to work out the mass of oxygen.

1. Second step

Mᵣ: 55.84

Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂

m/kg: 7.0

(a) Moles of Fe

$\text{Moles of FeO} = \text{7000 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.84 g Fe}} = \text{125 mol Fe}$

(b) Moles of CO

$\text{Moles of CO} = \text{125 mol Fe} \times \dfrac{\text{3 mol CO}}{\text{2 mol Fe}} = \text{188 mol CO}$

However, this is the theoretical yield.

The actual yield is 72. %.

We need more CO and Fe₂O₃ to get the theoretical yield of Fe.

(c) Percent yield

$\begin{array}{rcl}\text{Percent yield} &=& \dfrac{\text{ actual yield}}{\text{ theoretical yield}} \times 100 \, \%\\\\ 72. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.72 &= &\dfrac{\text{188 mol}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{188 mol}}{0.72}\\& = & \textbf{261 mol}\\\\\end{array}$

We must use 261 mol of CO to get 7.0 kg of Fe.

2. First step

Mᵣ: 32.00

2C + O₂ ⟶ 2CO

n/mol: 261

(a) Moles of O₂

$\text{Moles of O}_{2} = \text{261 mol CO} \times \dfrac{\text{1 mol O}_{2}}{\text{2 mol CO}} = \text{131 mol O}_{2}$

(b) Mass of O₂

$\text{Mass of O}_{2}= \text{131 mol O }_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \text{4180 g O}_{2}$

However, this is the theoretical yield.

The actual yield is 71. %.

We need more C and O₂ to get the theoretical yield of CO.

(c) Percent yield

$\begin{array}{rcl}71. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.71 &= &\dfrac{\text{4180 g}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{4180 g}}{0.71}\\\\& = & \text{5900 g}\\& = & \textbf{5.9 kg}\\\end{array}$

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.

6 0

4 years ago

Distillation is a _____________ separation technique.

Annette [7]

Answer:

physical

Explanation:

5 0

3 years ago

Read 2 more answers

Determine the mass percent composition of a solution made by dissolving 40.1g of LiOH in 681g of H2O

Lapatulllka [165]

<h3>Answer:</h3>

5.89%

<h3>Explanation:</h3>

We are given;

Mass of the solute, LiOH as 40.1 g
Mass of the solvent, H₂O as 681 g

We are required to calculate the mass percent composition of solution;

But; How do we calculate the mass percent composition of a solution?
We use the formula;

Mass composition of a solution = (Mass of solute/mass of solution) 100%

Therefore;

Mass Percent = (40.1 g/681 g)× 100%

= 5.888 %

= 5.89%

Therefore, the mass percent composition of the solution is 5.89%

7 0

3 years ago

Find the number of moles in 1.00 x 1023 atoms of chromium.

IRISSAK [1]

Answer:

<h2>0.17 moles</h2>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

We have

$n = \frac{1.00 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1}{6.02} \\ = 0.166112$

We have the final answer as

<h3>0.17 moles</h3>

Hope this helps you

8 0

3 years ago

Which of the following would have the highest lattice energy?

Ilia_Sergeevich [38]

Answer:

MgN3

Explanation:

In MgN3 the charge on the ionic species is greater than NaCl. So,ionic interactions in MgN3 will be stronger

4 0

3 years ago