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3 years ago

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The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction. This can be gleane

d from the third postulate in Dalton's series. Magnesium oxide decomposes into magnesium and oxygen. If 16.12 g of magnesium oxide decomposes to form 9.72 g of magnesium, what mass of oxygen gas is also released in the reaction?

1 answer:

GenaCL600 [577]3 years ago

8 0

Answer : The total mass of oxygen gas released in the reaction will be, 12.8 grams

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$2MgO\rightarrow 2Mg+O_2$

According to the law of conservation of mass,

Total mass of reactant side = Total mass of product side

Total mass of $2MgO$ = Total mass of $2Mg+O_2$

or,

Total mass of $2MgO$ = Mass of $2Mg$ + Mass of $O_2$

As we are given :

Total mass of $MgO$ = 16.12 grams

The mass of $Mg$ = 9.72 grams

So,

Total mass of $2MgO$ = Mass of $2Mg$ + Mass of $O_2$

$2\times 16.12g=2\times 9.72g+\text{Mass of }O_2$

$\text{Mass of }O_2=32.24g-19.44g=12.8g$

Therefore, the total mass of oxygen gas released in the reaction will be, 12.8 grams

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When 4.15 grams of silver nitrate is reacted with 1.11 grams of iron(III) chloride, which best represents the amount of silver c

PolarNik [594]

Answer:

The mass of silver chloride produced = 2.202 g

Explanation:

Equation of the reaction is given below

3AgNO₃(aq) + FeCl₃(aq) ----> 3AgCl(s) + Fe(NO₃)₃(aq)

molar mass of AgNO₃ = 170 g/mol

molar mass of FeCl₃ = 233.5 g/mol

molar mass of AgCl = 143.5 g/mol

3 moles of silver nitrate reacts with 1 mole of iron (iii) chloride to give 3 moles of silver nitrate

4.15 grams of AgNO₃ = 4.15/170 = 0.0244 moles of AgNO₃

1.11 grams of FeCl₃ = 1.11/233.5 = 0.0047 moles of FeCl₃

mole ratio of AgNO₃ to FeCl₃ = 0.0244/0.0047 = 5 : 1

therefore, FeCl₃ is the limiting reactant

0.0047 moles of FeCl₃ reacting will produce 0.0047 * 3 moles of AgCl = 0.0141 moles of AgCl

0.0141 moles of AgCl = 0.0141 * 143.5 g of AgCl = 2.02 g of AgCl =

Therefore mass of silver chloride produced = 2.202 g

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3 years ago

Mixtures of benzene and cyclohexane exhibit ideal behavior. A solution was created containing 1.5 moles of liquid benzene and 2.

goblinko [34]

Answer:

Vapour pressure of cyclohexane at 50°C is 490torr

Vapour pressure of benzene at 50°C is 90torr

Explanation:

Using Raoult's law, pressure of a solution is defined by the sum of the product sbetween mole fraction of both solvents and pressure of pure solvents.

$P_{solution} = X_{A}P^0_{A}+X_{B}P^0_{B}$

In the first solution:

$X_{cyclohexane}=\frac{2.5mol}{2.5mol+1.5mol} =0.625$

$X_{benzene}=\frac{1.5mol}{2.5mol+1.5mol} =0.375$

$340torr = 0.625P^0_{A}+0.375P^0_{B}$ <em>(1)</em>

For the second equation:

$X_{cyclohexane}=\frac{3.5mol}{3.5mol+1.5mol} =0.700$

$X_{benzene}=\frac{1.5mol}{3.5mol+1.5mol} =0.300$

$370torr = 0.700P^0_{A}+0.300P^0_{B}$ <em>(2)</em>

Replacing (2) in (1):

$340torr = 0.625P^0_{A}+0.375(1233.3-2.333P^0_{A})$

$340torr = 0.625P^0_{A}+462.5-0.875P^0_{A}$

-122.5torr = -0.250P°A

$P^0_{A} = 490 torr$

<em>Vapour pressure of cyclohexane at 50°C is 490torr</em>

And for benzene:

$370torr = 0.700*490torr+0.300P^0_{B}$

$P^0_{B}=90torr$

<em>Vapour pressure of benzene at 50°C is 90torr</em>

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