Chemistry Year 10 Flashcards
Physical change
No new substance made Reversible Change in state No fizzing or bubbling No colour change
Chemical change
Energy change Non reversible New substance made Precipitate formed Fizzing or bubbling Colour change
Universal indicator
ACID = red or orange BASE = blue or purple NEUTRAL = green
pH scale
1-6 = ACID 1= strong acid, 6= weak
7= NEUTRAL
8-14 = BASE 8 = weak 14 = strong base
Discuss OH-
Hydroxide ions, a BASE.
OH- ions released when put in water
Remove the H+ ions from a substance
Discuss H+ ions
Hydrogen ions
Are an ACID
H+ ions released when put in water
Properties of acids
Turn blue litmus paper red
Have a sour taste
Produce hydrogen when mixed with a metal
Produce CO2 when mixed with carbonate (marble chips)
Organic acid
Usually weak
Are found in nature
Contain carbon
Mineral acid
Usually strong (eg hydrochloride acid HCl)
Acid + base =
Water + salt
Acid + metal =
Hydrogen + salt
Acid + carbonate =
Water + salt + carbon dioxide (CO2)
Metal + oxygen =
Metal oxide
Metal + water =
Metal hydroxide + hydrogen
HCl + KOH/
Hydrochloric acid + potassium hydroxide =
H2O + KCl/
Water + potassium chloride
H2SO4 + CuCo3/
Sulfuric acid + copper carbonate =
H2O + CO2 + CuSO4/
Water + carbon dioxide + copper sulphate
HNO3 + Mg/
Nitric acid + magnesium =
H2O + MgNO3/
Water + magnesium nitrate
Testing for HYDROGEN
Hydrochloric acid (HCl) and magnesium (Mg) together makes hydrogen. To test for H2, light a match near the top of the test tube and it will make a pop noise
Testing for Carbon Dioxide
Hydrochloride acid (HCl) and marble chips (ClCO3) together make carbon dioxide (CO2). Bubble it throu lime water & if it turns milky it is CO2.
What is O+ ?
Oxide
What is OH-?
Hydroxide
What is SO4 ?
Sulphate
What is CO3 ?
Carbonate
What is NO3 ?
Nitrate
How and why do atoms and molecules form ions?
Because they do not have a full outer shell. They will either lose or gain electrons to make a full outer shell. That means they will turn positive or negative.
If they lose electrons, they become positive
If they gain electrons, they become positive
Household acids
Vinegar Tartaric acid Citric acid Tomato juice Orange juice Fizzy drink
Household bases
Bases have a soapy feel, so any cleaning product is normally a base
Eg handy Andy, janola
Nail polish remover Oven cleaner Bleach Toothpaste Detergent Shampoo
List some metals from MOST reactive to LEAST reactive
{MOST REACTIVE }. Ca -> Mg -> Al -> Zn -> Fe -> Cu -> Au {LEAST REACTIVE }
Calcium -> magnesium -> aluminium -> zinc -> iron -> copper -> gold
Discuss SHERBET
Sherbet contains an acid (citric acid) & a carbonate (NaHCO3). When combined, these make carbon dioxide (CO2), which creates the frothing in the mouth.
The other acid on its own (tartaric acid) creates the sour taste and the icing sugar causes the sweet taste.
Your tongue becomes wet because the acid and the carbonate (citric acid and baking soda) together, also make water (H2O).
The salty aftertaste is also because the acid and carbonate together also make a salt.
What is the COLLISION THEORY?
Rates of reaction are directly proportional to the amount of collisions between atoms in a reaction.
Name three ways the rate of collision (reaction) may be increased.
(Nb Collision Theory = rates of reaction are directly proportional to the amount of collisions between atoms in a reaction).
- INCREASE TEMPERATURE. The atoms speed up and therefore more likely to collide with other atoms. They have more energy.
- INCREASE CONCENTRATION. There are more atoms, so more collisions.
- INCREASE SURFACE AREA. There are more atoms available for collisions.
Discuss NEUTRALISATION.
BASES have the opposite properties to ACIDS.
BASES remove ACID particles from a solution.
A BASE is called an ALKALI if it can be dissolved in water. The resulting solution is ALKALINE. All alkaline solutions have pH higher than 7.
BASES can neutralize ACIDIC solutions by removing the H+ ions (acidic particles). When a base dissolves in water, it releases hydroxide ions (OH-). These combine with the free H+ ions to make water (H2O) with a pH equal to 7.
