A chemist prepares hydrogen fluoride by means of the following reaction: CaF2 + H2SO4 --> CaSO4 + 2HF

The chemist uses 11 g of CaF2 and an excess of H2SO4, and the reaction produces 2.2 g of HF.

(a) Calculate the theoretical yield of HF

(b) Calculate the percent yield of HF

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

1) according to the law of conservation of mass ,in all chemical reactions total mass is unchanged

The product formed when bao and h2o  react together is                        ba(oh)2that is  bao + h2o = ba(oh)21 mole of    bao    react  1 mole of h2o  to    form  1 mole  of ba(oh)2