Hii pls help me to balance chemical equations

ammonia + oxygen > nitrogen + water​

Asa choose the correct set of reaction coefficients to properly balance the following chemical equation according to the law of conservation of mass: __s8 + __o2 ==> __so2 1, 1, 8 1, 8, 1 1, 8, 8 8, 1, 1

Balance and in which category does it fit in? single or double displacement or synthesis or decomposition? (a) k2 o → k + o2 (b) na + i2 → nai (c) cu(no3 )2 + naoh → cu(oh)2 + nano3 (d) kclo3 → kcl + o2 (e) ca(no3 )2 + hbr → cabr2 + hno3 (f) sn(oh)2 → sno + h2 o (g) p4 + n2 o → p4 o6 + n2 (h) fe + al2 (so4 )3 → feso4 + al (i) alcl3 + na2 co3 → al2 (co3 )3 + nacl (j) c3 h6 + o2 → co2 + h2 o

Astudent conducts an experiment to determine how the amount of water given to a plant affects its growth. what is the independent variable for this experiment?