Question

1. the correct chemical formula for carbon disulfide is

cs₂
c₂s₂

1. the correct chemical formula for hydrogen iodide is

hi
hi₂

1. the correct chemical formula for zinc phosphate is

zn₃(po₄)₂
zn(po₂)₂

Explanation:

Question 6

Carbon disulfide consists of one carbon (C) atom and two sulfur (S) atoms. The prefix "di-" in "disulfide" indicates two sulfur atoms, so the formula is \( CS_2 \), not \( C_2S_2 \) (which would imply two carbon and two sulfur atoms, inconsistent with the name).

Hydrogen iodide is a binary compound of hydrogen (H, with a +1 charge) and iodine (I, with a -1 charge in this compound). To balance charges, one H and one I combine, giving the formula \( HI \). \( HI_2 \) would imply an incorrect charge balance (H⁺ and two I⁻ would need a 2+ charge on H, which is not the case).

Zinc (Zn) has a +2 charge, and the phosphate ion is \( PO_4^{3-} \). To balance charges, we need 3 Zn²⁺ ions (total +6 charge) and 2 \( PO_4^{3-} \) ions (total -6 charge), giving \( Zn_3(PO_4)_2 \). \( Zn(PO_2)_2 \) involves the wrong polyatomic ion (phosphite-like, not phosphate) and incorrect charge balancing.

Answer:

A. \( CS_2 \)

Question 7