Determine if the highlighted element in the first compound of each reaction was oxidized or reduced. (a) mg(s) nicl2(aq) ⟶ mgcl2(aq) ni(s) (b) pcl3(l) cl2(g) ⟶ pcl5(s) (c) c2 h4(g) 3o2(g) ⟶ 2co2(g) 2h2 o(g) (d) zn(s) h2 so4(aq) ⟶ znso4(aq) h2(g) (e) 2k2 s2 o3(s) i2(s) ⟶ k2 s4 o6(s) 2ki(s) (f) 3cu(s) 8hno3(aq) ⟶ 3cu(no3)2(aq) 2no(g) 4h2 o(l)

Match the words in the left column to the appropriate blanks in the sentences on the right. (a) this is the law of definite proportions: all samples of a given compound, regardless of their source or how they were prepared, have proportions of their constituent elements. (b) this is the law of conservation of mass: in a reaction, matter is neither created nor destroyed. (c) this is the law of multiple (c) this is the law of multiple blank: when two elements form two different compounds, the masses of element b that combine with 1 g of element a can be expressed as a ratio of small whole-numbers. in this example, the ratio of \rm o from hydrogen peroxide to \rm o from water = 16: 8 \to 2: 1, a small whole-number ratio.: when two elements form two different compounds, the masses of element b that combine with 1 g of element a can be expressed as a ratio of small whole-numbers. in this example, the ratio of o from hydrogen peroxide to o from water = 16: 8 → 2: 1, a small whole-number ratio.