The molarity of a solution prepared by dissolving 141.6g of citric acid in water is calculated as below
find the the number of moles
moles= mass/molar mass
= 141.6 g/ 192 g/mol = 0.738 moles
molarity= moles/molar mass
= 0.738/3500 x1000 = 0.21 M
The reaction of hydrogen gas (H2) with oxygen gas (O2) is a COMBINATION or SYNTHESIS reaction, because multiple substances combine to form fewer substances. Here, the two gases form one substance, water (H2O):
2H2 + O2 -- > 2H2O
D=mxv so your answer should be 269.37