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3 years ago

What is the mass of a 2.5 mole sample of MgO2

Chemistry

1 answer:

MrRa [10]3 years ago

6 0

Mass = no. of moles x molecular weight
m = n x Mr
m = 2.5 mol x (24 + [16 x 2])
m = 140g

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An analytical chemist is titrating of a solution of propionic acid with a solution of 224.9 ml of a 0.6100M solution of propioni

Svetllana [295]

Answer: The pH of acid solution is 4.58

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ .....(1)

For KOH:

Molarity of KOH solution = 1.1000 M

Volume of solution = 41.04 mL

Putting values in equation 1, we get:

$1.1000M=\frac{\text{Moles of KOH}\times 1000}{41.04}\\\\\text{Moles of KOH}=\frac{1.1000\times 41.04}{1000}=0.04514mol$

For propanoic acid:

Molarity of propanoic acid solution = 0.6100 M

Volume of solution = 224.9 mL

Putting values in equation 1, we get:

$0.6100M=\frac{\text{Moles of propanoic acid}\times 1000}{224.9}\\\\\text{Moles of propanoic acid}=\frac{0.6100\times 224.9}{1000}=0.1372mol$

The chemical reaction for propanoic acid and KOH follows the equation:

$C_2H_5COOH+KOH\rightarrow C_2H_5COOK+H_2O$

Initial: 0.1372 0.04514

Final: 0.09206 - 0.04514

Total volume of solution = [224.9 + 41.04] mL = 265.94 mL = 0.26594 L (Conversion factor: 1 L = 1000 mL)

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[acid]})$

$pH=pK_a+\log(\frac{[C_2H_5COOK]}{[C_2H_5COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of propanoic acid = 4.89

$[C_2H_5COOK]=\frac{0.04514}{0.26594}$

$[C_2H_5COOH]=\frac{0.09206}{0.26594}$

pH = ?

Putting values in above equation, we get:

$pH=4.89+\log(\frac{(0.04514/0.26594)}{(0.09206/0.26594)})\\\\pH=4.58$

Hence, the pH of acid solution is 4.58

7 0

4 years ago

What is the molarity of 0.26 mol of H2SO4 dissolved in 0.3 L of solution? *

irina1246 [14]

Answer:

Explanation:

molarity=moles of solute/liter of solution

molarity=0.26/0.3

molarity=0.87molar

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3 years ago

How many moles are there in 32.4 grams of Na

Natalija [7]

Divide that my the molar mass which is 23 so 1.4087 g

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3 years ago

Which property of fossil fuel make them an important resource for life on earth

grandymaker [24]

Fossil Fuels give off energy when they are burned

One valuable fossil fuel is natural gas. It is a cleaner-burning fuel source.

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3 years ago

If you sprayed an air freshener, where would the highest concentration of air freshener be found?

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FLOOR. Most of the molecules that dont sick to something fall on the floor so most would be on the FLOOR.

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3 years ago