Writing Chemical Formulae and Equations

Question 1

what is a compound

Answer 1

pure substance made up of 2 or more different elements chemically combined in a fixed ratio

Question 2

what are 2 types of compounds

Answer 2

covalent compounds
ionic compounds

Question 3

2 points

how are covalent compounds named

Answer 3

suffix “-ide” for covalent compounds containing only 2 different non-metallic elements

prefix “mono- (1) / di- (2) / tri- (3) /tetra- (4)” to represent amount of atoms in that element

Question 4

what are the 4 covalent compounds that do not follow the naming convention

Answer 4

methane: CH₄
ammonia: NH₃
water: H₂O
glucose: C₆H₁₂O₆

Question 5

what are 7 common elements which form diatomic molecules

Answer 5

Hydrogen: H₂
Nitrogen: N₂
Oxygen: O₂
Fluorine: F₂
Chlorine: Cl₂
Bromine: Br₂
Iodine: I₂

Question 6

2 points

what are the characteristics of the charges of ionic compound

Answer 6

made up of ions (electrically charged particles, carries either positive or negative charge)

sum of positive charges must equal sum of negative charges

Question 7

what are the charges for elements in group 1-2, 13-17

Answer 7

group 1:
+1 (Li⁺, Na⁺, K⁺)

group 2:
+2 (Mg²⁺, Ca²⁺, Ba²⁺)

group 13:
+3 (Al³⁺)

group 14:
tend not to form ions (form covalent compounds instead)

group 15:
-3 (N³⁻)

group 16:
-2 (O²⁻, S²⁻)

group 17:
-1 (F⁻, Cl⁻, Br⁻)

*(II) or (III) represents positive charge of that value [i.e. iron(II) = Fe²⁺]

Question 8

what is the charge of ammonium

Answer 8

NH₄⁺

Question 9

what is the charge of silver

Answer 9

Ag⁺

Question 10

what is the charge of zinc

Answer 10

Zn²⁺

Question 11

what is the charge of hydroxide

Answer 11

OH⁻

Question 12

what is the charge of nitrate

Answer 12

NO₃⁻

Question 13

what is the charge of carbonate

Answer 13

CO₃²⁻

Question 14

what is the charge of sulfate

Answer 14

SO₄²⁻

Question 15

what is the method to balance charges of ions on ionic compounds

Answer 15

Xᵐ⁺ + Yⁿ⁻ = XₙYₘ

Question 16

what does the Law of Conservation of Matter state

Answer 16

matter cannot be created or destroyed in any chemical reaction

*chemical reactions involve a rearrangement of atoms which are not created or destroyed

Question 17

why should a → be used instead of = in chemical equations

Answer 17

the reactants are not equal to the products, the arrow represents the progression from the reactants to the products