Chemistry problem (1 Viewer)

[Real Madrid]

Dilute hydrochloric acid was added to zinc until no further reaction occured.

What mass of zinc chloride would be produced if 0.040 mole of hydrochloric acid reacted with excess zinc?

I balanced the equation to 2HCl + Zn -> ZnCl2 + H2.
_____________________ 0.040__?_____?_____?

How do I know how many moles are the other compounds and elements?

 

[st1m]

ratio of hydrochloric acid to Zinc chloride for example is 2:1

which means that there are 2 moles of HCL to 1 of Zinc chloride.

therefore 0.040 * 1/2= number of moles of Zinc chloride.

Mole= Mass/molar mass

therefore Molar mass * mole= Mass

Molar mass of Zinc chloride= check the back of your book

Mole of Zinc chloride= 0.040 * 1/2

therefore: Molar mass of Zinc chloride * 0.040* 1/2= Mass of Zinc chloride.

Note... the only challenge is balancing and getting the equation right.

the rest is easy.

 

[kaz1]

If there is 0.04 mol of HCl using stoichiometry there would be 0.02mol of ZnCl2 because the ratio between HCl and ZnCl2 is 2:1.

Using m= Mn

m = 0.02 x (65.41) + (35.45 x 2)
m= 2.73g of ZnCl2

I think that is right.

 

[st1m]

doesn't look right... its 0.040 not 0.4

 

[kaz1]

doesn't look right... its 0.040 not 0.4

lol read the question wrong.