PLSSS HELP ASAPP ITS 200 points and I give brainlist

Feb 25th and 26th Honors Chemistry Assignment
Follow the given steps:
Balance the equations.
Calculate the molar mass of substances involved.
Use the mole ratios between substances involved to solve the problems.



Given the following reaction:
_Na2S2O3 + _AgBr __NaBr + __Na3[Ag(S2O3)2]

a. How many moles of Na2S2O3 are needed to react completely with 40.7 g of AgBr?

b. What is the mass of NaBr that will be produced from 40.7 g of AgBr?





2. From the reaction: _B2H6 + _O2 _HBO2 + _H2O

a. What mass of O2 will be needed to burn 30.5 g of B2H6?

b. How many moles of water are produced from 20 g of B2H6?