How many moles of calcium are there in 5.00 g of Ca?

Answer 1

Percent CompositionFirst you have to find all the atomic masses of the elements involved in the compound. Then you have to add them up to get the total molecular mass. Take the Atomic Mass of Ca and divide it by the total mass. Multiply it by 100 and you will get the percent of Ca in any compound of Ca(OH)2. Once you know the percent composition, you can take Ca's percent from the whole sample.

Ca: 40.1

O: 16.0×2 = 32.0

H2: 1.0×2 = 2.0

Ca(OH)2: 74.1 grams

(40.1 ÷ 74.4) × 100 = 53.9 % of Ca in Ca(OH)2

53.9 % of 5.00 grams = 2.67 grams of Ca in Ca(OH)2

Answer 2

0.5000g Ca(OH)2 (1mol Ca(OH)2/74.096g)(1mol Ca/1mol Ca(OH)2)(6.022 X 10^23/1mol Ca)(1mol Ca/6.022 X 10^23)

= 0.0067 moles of calcium ions

Answer 3

molar mass Ca = 40.078g/mol

5.00g Ca x (1mol/40.078g) = 0.125mol Ca

Answer 4

5.00 grams calcium (1 mole Ca/40.08 grams)

= 0.125 moles calcium

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Answer 5

0.125 mol Ca

Answer 6

5/40=0.125mol

Answer 7

0.125