Ireally do not know how to do this, i already asked my teacher to explain it to me, but i still don’t understand. can someone me i would be very grateful.

1. to calculate molar mass , you need average atomic mass of each element.

formula is simple

suppose we have Na2CO3

here it says

there are

2 atoms of Na

1 atom of C

3 atom of O

now

molar mass = (total atoms of Na × average atomic mass of Na) + ( total atom of C × average atomic mass of C )+ (total atom of O × average atomic mass of O)

i hope you can figure out it now.

in case of (NH4)2

this means you have 2 count of NH4

so total atoms of N = 2

total atoms of H = 4×2 = 8

so on you can now figure it out

2. balanced equation

here LHS and RHS shoild have same number of atoms of each element .

for example

H2 + Cl2 => 2HCl

here 2 atoms of H combined with 2 atoms of Cl , we know H and Cl combined and formed HCl now because total H atoms are 2 and Cl atoms are 2 in LHS then we should also have 2 atoms of each in right side

so thats why we have 2HCl in right side.

Try to figure out . let me know if need any help

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.