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This quiz contains 12 questions from a mix of 1 subtopics.

Phosphorus reacts with oxygen to give a compound that is 43.7% phosphorus and 56.3% oxygen.

What is the empirical formula of the compound?

P2O5

PO

P1O2.5

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What is the empirical formula of a compound that contains 15.9% boron and 84.1% fluorine?

B2F3

B3F

BF3

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What is the empirical formula of a compound that contains 46.3% lithium and 53.7% oxygen?

Li2O2

Li2O4

Li2O

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Compound X has the following percentage by mass composition: C: 40.0%; H: 6.7%; O: 53.3%. 

Deduce the empirical formula of compound X.

CH2O

CHO

C6HO8

C2H4O

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Compound X has an empirical formula of CH2O and a relative molecular mass of 180.0. 

Deduce the molecular formula of compound X.

C6H12O6

6(CH2O)

C6H6O6

C12H12O12

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Compound Y contains 52.2 g of carbon, 13.0 g of hydrogen and 34.8 g of oxygen.

Deduce the empirical formula of compound Y.

C2H3O

C3H6O2

C2H6O

CH3O

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Select the correct formula for hydrated copper(II) sulfate.

CuSO4

CuSO45H2O

CuSO4 + 5H2O

CuSO4•5H2O

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Select the correct formula for anhydrous cobalt(II) chloride.

Co2Cl22H2O

CoCl22H2O

CoCl2

Co2Cl2

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A 1.20 g sample of hydrated tin chloride is heated, causing it to decompose and form 1.01 g of anhydrous tin chloride:

SnCl2nH2O ➔ SnCl2 + nH2O

Work out the value of n.

The formula of the hydrated compound is SnCl2H2O

2

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3.74 g of hydrated copper sulfate is heated to form 2.39 g of anhydrous copper sulfate:

CuSO4nH2O ➔ CuSO4 + nH2O

Work out the value of n.

The formula of the hydrated compound is CuSO4H2O

5

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4.92 g of hydrated magnesium sulfate was heated to remove the water, producing 2.40 g of anhydrous magnesium sulfate.

Work out the value of n.

The formula of the hydrated compound is MgSO4H2O

7

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A 4.31 g sample of hydrated Na2CO3 is heated to remove the water. The mass of the resulting anhydrous compound is 3.22 g.

What is the formula of the hydrated compound?

The formula of the hydrated compound is Na2CO3H2O

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