acids and alkalis

Question 1

what is the formula for hydrochloric acid

Answer 1

HCl (aq)

Question 2

what do we write next to an acids formula in chemistry and what does this mean

Answer 2

(aq) aqueous solution

dissolved in water

Question 3

what are the 3 main acids we use in chemistry

what are the chemical formulas for them

Answer 3

Hydro chloric acid = HCl(aq)
Sulphuric acid = H2SO4(aq)
Nitric acid = HNO3(aq)

Question 4

what do acids produce in aqueous solutions?

Answer 4

hydrogen ions (H+)

Question 5

show the reaction of hydrochloric acid in an aqueous solution

explain what is happening

Answer 5

HCl(aq) —> H+(aq) + Cl-(aq)

the molecule has split and released the hydrogen ion (H+)
We make the chloride ion Cl-

Question 6

what happens to molecules in acids when in an aqueous solution?

Answer 6

molecules split to form H+(aq) and acid-(aq)

Question 7

write the reaction of sulphuric acid in an aq

H2SO4

Answer 7

produces positive hydrogen ion and negative sulphate ion

H2SO4(aq)—> 2H+(aq) + SO4^2-(aq)

Question 8

show nitric acid in an aqueous solution

HNO3(aq)

Answer 8

HNO3(aq)—> H+(aq) + NO3-(aq)

we produce a positive hydrogen ion and a negative nitrate ion

Question 9

what do bases do

what are bases

Answer 9

chemicals that neutralise acids producing a salt and water

usually they are metal oxides or metal hydroxides

Question 10

what are alkalis

Answer 10

bases that are soluble in water

Question 11

what are bases which are soluble in water called

Answer 11

alkalis

Question 12

iron (III) hydroxide is insoluble one water

is this a base or an alkali

Answer 12

a base

Question 13

sodium hydroxide is soluble in water, does this make sodium hydroxide a base or an alkali?

Answer 13

both a base and an alkali

it neutralises acids producing a salt (sodium) and a water (hydrogen + oxygen)
and is also soluble in water

Question 14

what do alkalis produce in aqueous solutions?

Answer 14

hydroxide ions (OH-)

Question 15

show the base/alkali sodium hydroxide in an aqueous solution

Answer 15

NaOH(aq)—> Na+(aq) + OH-(aq)

the sodium hydroxide is splitting and produces the positive sodium ion (Na+) and the negative hydroxide ion
OH- (aq)

Question 16

aqueous solutions of ______ produce the hydroxide ion OH-

Answer 16

alkalis

Question 17

what can a pH be useful for

Answer 17

to tell us the acidity or alkalinity of a solution
acids pH (0-6)
neutral (7)
alkaline (8-14)

Question 18

what does a pH probe do

Answer 18

determines the pH electronically

Question 19

name 1 way we can determine whether a solution is acid alkali or neutral

Answer 19

using a universal indicator

red - very acidic
yellow - acidic
green - neutral 
blue - alkaline 
purple - very alkaline

Question 20

describe and show the neutralisation reaction of an acid and an alkaline

Answer 20

from acid. from the alkali

H+(aq) + OH-(aq) —> H2O(l)
hydrogen hydroxide water
ion ion

alkalis produce the hydroxide ion OH-
when we react an acid with an alkali, the hydrogen ions react with the hydroxide ions to produce water

Question 21

what is the equation for neutralisation.

NEED TO LEARN

Answer 21

H+(aq) + OH-(aq) —> H2O(l)
hydrogen. hydroxide water
ion ion

Question 22

what do all acids contain

Answer 22

hydrogen