Balancing equations? I don't understand?

Question

Choose the correct coefficients to balance the following equation: __Zn + __HCl ---> __ZnCl2 + __H2.

A) 1, 2, 2, 2
B) 1, 2, 1, 1
C) 2, 4, 2, 2
D) 0, 2, 0, 0

I think it's either B or D. Can anyone help me please?

Answer 1

Think of the --> as a fulcrum and you need to make sure you have the same number of atoms of the left hand side as on the right hand side it's that easy.



Zn + HCl --> ZnCl2 + H2



so we have 2 Hydrogens on the right so we need at least 2 hydrogens on the left. We also have 2 chlorines on the right so we need 2 chlorines on the left. So it's easy.



Zn + 2HCl --> ZnCl2 + H2



So your answer is 1,2,1,1



your answer is B).

Answer 2

Keep an account of the number of each element. If you do this you will see that there are 2 x the number of H and Cl on the right side vs the left side so the only way to correct it is to double the number on the left. Choose B

Answer 3

It is B, like the other two answers explained.



Remind yourself that NONE of the coefficients should ever be zero. If there is none of it, the formula or symbol would not be written at all!!

Answer 4

It's C actually :)