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3 years ago

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Calculate the number of moles of caco3 (calcium carbonate, or limestone) in a 20.0g sample of this substance

1 answer:

Brrunno [24]3 years ago

6 0

First calculate for the molar mass of the given formula unit, CaCO₃. This can be done by adding up the product when the number of atom is multiplied to its individual molar mass as shown below.

molar mass of CaCO₃ = (1 mol Ca)(40 g Ca/mol Ca) + (1 mol C)(12 g of C/1 mol of C) + (3 mols of O)(16 g O/1 mol O) = 100 g/mol of CaCO₃

Then, divide the given amount of substance by the calculated molar mass.
number of moles = (20 g)(1 mol of CaCO₃/100 g)
number of moles = 0.2 moles of CaCO₃

<em>Answer: 0.2 moles</em>

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The statement is false as 85675 grams of nitrogen dioxide is produced instead of 20 grams.

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2NO + $O_{2}$ ⇒ 2N $O_{2}$

Data given:

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mass of oxygen = 29.8 litres or 29800 grams

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putting the values in the equation:

= $\frac{29800}{32}$

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Calculate the volume of 4.00 molar NaOH solution required to prepare 100 mL of a 0.500 molar solution of NaOH.

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Answer:

The answer to your question is V₁ = 12.5 ml

Explanation:

Data

Volume = V₁?

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Volume 2 = V₂ = 100 ml

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Formula of dilution

V₁C₁ = V₂C₂

Solve for V₁ (original solution)

V₁ = $\frac{V2C2}{C1}$

Substitution

V₁ = $\frac{(0.5)(100)}{4}$

Simplification

V₁ = $\frac{50}{4}$

Result

V₁ = 12.5 ml

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3 years ago