I really need the help, come on please, I got a Walmart gift CARD for anyone who can fill this out correctly Balancing Equations Worksheet
1) Na3PO4 + KOH → NaOH + K3PO4
2) MgF2 + Li2CO3 → MgCO3 + LiF
3) P4 + O2 → P2O3
4) RbNO3 + BeF2 → Be(NO3)2 + RbF
5) AgNO3 + Cu → Cu(NO3)2 + Ag
6) CF4 + Br2 → CBr4 + F2
7) HCN + CuSO4 → H2SO4 + Cu(CN)2
8) GaF3 + Cs → CsF + Ga
9) BaS + PtF2 → BaF2 + PtS
10) N2 + H2 → NH3
11) NaF + Br2 → NaBr + F2
12) Pb(OH)2 + HCl → H2O + PbCl2
13) AlBr3 + K2SO4 → KBr + Al2(SO4)3
14) CH4 + O2 → CO2 + H2O
15) Na3PO4 + CaCl2 → NaCl + Ca3(PO4)2
16) K + Cl2 → KCl
17) Al + HCl → H2 + AlCl3
18) N2 + F2 → NF3
19) SO2 + Li2Se → SSe2 + Li2O
20) NH3 + H2SO4 → (NH4)2SO4

1) 1 Na3PO4 + 3 KOH  3 NaOH + 1 K3PO4

2) 1 MgF2 + 1 Li2CO3  1 MgCO3 + 2 LiF

3) 1 P4 + 3 O2  2 P2O3

4) 2 RbNO3 + 1 BeF2  1 Be(NO3)2 + 2 RbF

5) 2 AgNO3 + 1 Cu  1 Cu(NO3)2 + 2 Ag

6) 1 CF4 + 2 Br2  1 CBr4 + 2 F2

7) 2 HCN + 1 CuSO4  1 H2SO4 + 1 Cu(CN)2

Explanation:

8) 1 GaF3 + 3 Cs  3 CsF + 1 Ga

9) 1 BaS + 1 PtF2  1 BaF2 + 1 PtS

10) 1 N2 + 3 H2  2 NH3

11) 2 NaF + 1 Br2  2 NaBr + 1 F2

12) 1 Pb(OH)2 + 2 HCl  2 H2O + 1 PbCl2

13) 2 AlBr3 + 3 K2SO4  6 KBr + 1 Al2(SO4)3

14) 1 CH4 + 2 O2  1 CO2 + 2 H2O

15) 2 Na3PO4 + 3 CaCl2  6 NaCl + 1 Ca3(PO4)2

16) 2 K + 1 Cl2  2 KCl

17) 2 Al + 6 HCl  3 H2 + 2 AlCl3

18) 1 N2 + 3 F2  2 NF3

19) 1 SO2 + 2 Li2Se  1 SSe2 + 2 Li2O

20) 2 NH3 + 1 H2SO4  1 (NH4)2SO4

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.