Number of grams in 4 mols of cu(no2)2

151.55 x 4 you have to add the molar masses for each element together.

Their are 622.23 grams in 4 moles of Cu(NO2)2. Take the molar masses of all the elements and add them together. Then multiply by four because you have 4 moles not 1 mole. 

Hope this helps you :)