##### Calcium hydride reacts with water to form calcium hydroxide and hydrogen gas....

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Calcium hydride reacts with water to form calcium hydroxide and hydrogen gas.

(a) Write a balanced chemical equation for the reaction. (Use the lowest possible coefficients. Include states-of-matter under SATP conditions in your answer.)
(b) How many grams of calcium hydride are needed to form 6.491 g of hydrogen?
Jul 24th, 2015

a]CaH2 [s] +H2O[l] = Ca [OH] 2 [s] +2H2  [g]

b]2 moles of hydrogen is formed for every one mole of calcium hydride

CaH2+2H2
40+2 = 42 GRAMMES
Thus 4g= Hydrogen
42 /[ 6.491 /4]
42/ 1. 3

32 grammes
Jul 24th, 2015

Thats wrong

Jul 24th, 2015

Thats wrong

Jul 24th, 2015

67.77g This is what i got can you redo it maybe you did some mistake?

Jul 24th, 2015

ok. fine then. dont are me badly.

Jul 24th, 2015

No its not like that haha sorry if it sounded rude. I was just meaning to say I tried your answer into my computer assignment but it counted it wrong

Jul 24th, 2015

6.4919/1.008= 3.22moles of hydrogen used.

For I mole of calcium hydride, 2 moles of hydrogen was formed hence the amount of calcium hydride used in moles is 3.22/2=1.61 moles of calcium hydride.

Hence mass= moles *molar mass which is 1.61moles*42.094= 67.77g

This is the work i did - do you think this is right?

Jul 24th, 2015

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Jul 24th, 2015
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Jul 24th, 2015
Dec 11th, 2016
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