Chemical Reactions
In a chemical reactions, what are the substances before the arrow called?
Reactants
Change the following word equation into a skeleton equation. Balance.
Hydrogen plus oxygen yields water.
2H2 +O2 --> 2H2O
An acid starts with ______
hydrogen
What is balancing an equation?
Balancing an equation, means ensuring that the number of atoms of each element is the same on both sides of a chemical reaction.
The following is an example of an acid, base or salt?
H₂SO₄
acid
What does the Law of Conservation of Mass state?
The mass of the reactants will equal the mass of the products, in a closed system. Mass can not be created or destroyed.
Change the following word equation into a skeleton equation. Balancing is optional.
hydrogen fluoride + aluminum hydroxide --> aluminum fluoride + water
3HF + Al(OH)3 --> ALF3 + 3H2O
Which type of litmus paper do bases change, and what colour does it turn?
red litmus to blue
__ H2 + __ O2 -> __ H2O
2 H2 + __ O2 -> 2 H2O
Ca(OH)2 + H3PO4 --> Ca3(PO4)2 + H2O
Which of the following is a salt?
Ca3(PO4)2
When energy is written in the product, we say the reaction is __________?
Exothermic
Change the following word equation into a skeleton equation. Balancing is optional.
Gold (III) chloride + copper --> copper (II) chloride + gold
2AuCl3 + 3Cu --> 3CuCl2 + 2Au
Bases break apart to form which ion in a solution?
Hydroxide
How many atoms of each element are present?
4Al(OH)3
Al = 4
O = 3x4 = 12
H = 3x4 = 12
HCl + NaOH
Which is a base?
NaOH
What does the arrow, the "+" signs, and the (s) mean in a chemical equation?
arrow = produces
+ = and
(s) = solid
Change the following word equation into a skeleton equation. Balancing is optional.
Potassium + calcium chloride --> potassium chloride + calcium
2K + CaCl2 --> 2KCl + Ca
Which pH number is considered neutral 9,7,0,8?
7
How many atoms of each element are present?
2(NH4)3PO4
N = 6
H = 24
P = 2
O = 8Zn(OH)2 + H2SO3
Which is an acid and what is its name?
H2SO3 = sulfurous acid
What are two signs a chemical reaction has occurred?
Temperature change, release of light, odour change, gas given off (bubbles), colour change, etc.
Change the following word equation into a skeleton equation. Balancing is optional.
cesium sulphite + nickle (III) fluoride --> cesium fluoride + nickel (III) sulphite
3Cs2SO3 + 2NiF3 --> 6CsF + Ni2(SO3)3
Cleaners are usually acids, bases or salts?
bases
__ AI + __ H2 SO4 -> __ AI2(SO4)3 + __ H2
2 AI + 3 H2SO4 -> __ AI2(SO4)3 + 3H2
Name the following acids:
HNO3
HBr
HNO3 = nitric acid
HBr = hydrobromic acid