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2 years ago

How many formula units are present in 40.0 grams of Cu2S?

Chemistry

1 answer:

11Alexandr11 [23.1K]2 years ago

4 0

Never mind, I did the problem wrong, I deeply apologize.

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How to solve x² in differential

g100num [7]

Answer:

x² = mutiphy by them self

Explanation:

4 0

3 years ago

Silver metal can be prepared by reducing its nitrate, AgNO3 with copper according to the following equation:

Lerok [7]

%yield = 88.5%

<h3>Further explanation</h3>

Given

Reaction

Cu(s) + 2 AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s)

Required

The percent yield

Solution

mol AgNO₃(MW=169,87 g/mol) :

= mass : MW

= 127 : 169.87

= 0.748

mol Ag from equation :

= 2/2 x mol AgNO₃

= 2/2 x 0.748

= 0.748

Mass Ag (theoretical) :

= mol x Ar Ag

= 0.748 x 108

= 80.784

% yield = (actual/theoretical) x 100%

%yield = 71.5/80.784 x 100%

<em>%yield = 88.5%</em>

7 0

2 years ago

Which statement correctly describes measuring with a graduated cylinder?

snow_tiger [21]

Answer:

what are the options because a graduated cylinder is a science mixing cylinder is a common piece of laboratory equipment used to measure the volume of a liquid

Explanation:

6 0

2 years ago

The half-life of na-24 is 15 hours . when there are 1000 atoms of na-24 in a sample , a scientist starts a stopwatch . the scien

marin [14]

125 Each half life it divides by 2 the amount
1000/2=500
500/2=250
250/2=125

8 0

2 years ago

Read 2 more answers

Combustion reactions are exothermic. The heat of reaction for the combustion of 2-methylheptane, C8H18, is 1.306×103 kcal/mol. W

WARRIOR [948]

Answer:

11.45kcal/g

2.612 × 10³ kcal

Explanation:

When a compound burns (combustion) it produces carbon dioxide and water. The combustion of 2-methylheptane can be represented by the following balanced equation:

2 C₈H₁₈ + 25 O₂ ⇄ 16 CO₂ + 18 H₂O

It releases 1.306 × 10³ kcal every 1 mol of C₈H₁₈ that is burned.

<em>What is the heat of combustion for 2-methylheptane in kcal/gram?</em>

We know that the molar mass of C₈H₁₈ is 114.0g/mol. Then, using proportions:

$\frac{1.306 \times 10^{3}Kcal}{1mol} .\frac{1mol}{114.0g} =11.45kcal/g$

<em>How much heat will be given off if molar quantities of 2-methylheptane react according to the following equation? 2 C₈H₁₈ + 25 O₂ ⇄ 16 CO₂ + 18 H₂O</em>

In this equation we have 2 moles of C₈H₁₈. So,

$2mol \times\frac{1.306 \times 10^{3}kcal }{1mol} =2.612\times 10^{3}kcal$

3 0

2 years ago