Hich of the following equations is balanced correctly?

a.
2 c2h2 + 5 o2 → 4 co2 + 2 h2o

b.
3 h2o → h2 + 3 o2

c.
2 c3h3 + o2 → 2 co2 + h2o

d.
cl2 + 2 kbr → kcl + br2

The precision of a laboratory instrument is ± 0.05 g. the accepted value for your measurement is 7.92 g. which measurements are in the accepted range? check all that apply. 7.85 g 7.89 g 7.91 g 7.97 g 7.99 g