PLEASE PLEASE HELP WILL GIVE BRANLIEST in the reacion, Zn + 2 HCl --> ZnCl2 +H2
25 grams of Zn are reacted with 17.5 grams of HCl. how many grams of the excess reactant is left over?

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

Why is the melting of ice a physical change ?

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!