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antiseptic1488 [7]
2 years ago
14

Determine the percent composition of potassium dichromate, K2Cr2O7.

Chemistry
1 answer:
bulgar [2K]2 years ago
4 0

Answer:

Option E is the correct one

Explanation:

K₂Cr₂O₇ → Potassium dichromate

A ionic salt which its molar mass is 294.18 g/m

It is composed by 2 mol of K, 2 mol of Cr and 7 mol of O

2 mol of K = 78.2 g

2 mol of Cr = 104 g

7 mol of O = 112 g

In 294.2 g of compound we have __78.2 g K __ 104 g Cr ___ 112 g O

Let's calculate the percent

(78.2 / 294.2) .100 = 26.59% K

(104 / 294.2) .100 = 35.35% Cr

(112 / 294.2) . 100 = 38.06 % O

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Molecular mass of Mg(OH)2

= Atomic mass of Mg + 2(Atomic mass of O) + 2(Atomic mass of H)

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Answer:

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