Physical Changes
TRUE or FALSE: Ice melting is an example of a physical change.
True
TRUE or FALSE: Milk changing from white to black when Milo is dissolved is an example of chemical change
FALSE: it is due to dissolving which is a physical change as the brown Milo particles spread out amongst whe milk particles so the drink appears brown.
Copper sulphate reacts with an iron nail. The nail turns red and the liquid turns yellow.
Identify the reactants
copper sulfate and iron
Identify the products:
Carbon dioxide and water react to produce glucose and oxygen
Glucose and oxygen
Identify the reactants and products:
SO2 + O2 ---> SO3
Reactants = SO2 and O2
Product = SO3
List the four signs of physical change
Change in state, change in shap, expansion/contraction, mixing and dissolving.
What two things are true for all chemical reactions?
All chemical reactions are IRREVERSIBLE and a NEW substance is produced.
Copper sulphate reacts with an iron nail. The nail turns red and the liquid turns yellow.
What is the evidence of a chemical reaction occuring?
Permanent colour change.
New substance is formed.
Irreversible change
Identify the reactants:
Barium sulfate and sodium chloride are produced when sodium sulfate reacts with barium chloride.
Sodium sulfate and barium chloride.
Write the chemical equation from the following word equation:
glucose (C6H12O6) + oxygen ---> carbon dioxide + water
C6H12O6 + O2 ---> CO2 + H2O
What type of physical change is a balloon being blown up for a party an example of?
Expansion/contraction
Identify the five signs of chemical change
Permanenet colour change
Temperature change
Precipitate is formed
Gas is produced
Light or sound energy is released
Which option depicts a chemical reaction occuring?
A. Icicles melting
B. A beaker of water with no temperature change
C. Magnesium metal reacting to acid
C. Magnesium metal reacting to acid
Write the word equation:
Barium sulfate and sodium chloride are produced when sodium sulfate reacts with barium chloride.
sodium sulfate + barium chloride --> Barium sulfate + sodium chloride
Write a balanced chemical equation.
When hydrogen fluoride (HF) reacts with potassium carbonate (K2CO3), potassium fluoride(KF), water and carbon dioxide are formed.
2HF + K2CO3 ---> 2KF + H2O + CO2
Give an example of the each of the types of phhysical change that can be found at school
Something showing one of each of the following:
Change in state
Change in shape
Expansion/contraction
Mixing and dissolving
Explain what is happening when a glowstick is turned on and justify your choice using signs of change.
When a glowstick is snapped, the barrier between two substances is broken and they mix together. They react and light is produced when a new substance is formed.
A chemical reaction has taken place. What happened to the atoms in the reactants?
A. they stay joined / bonded to the same atoms
B. the atoms are rearranged and bonded to the different atoms
C. the atoms get destroyed
B. the atoms are rearranged and bonded to the different atoms
Write the word equation (include states):
Heating solid copper carbonate makes solid copper oxide and carbon dioxide.
copper carbonate(s) ------> copper oxide(s) + carbon dioxide(g)
*condition = heating (above the arrow)
Write a balanced chemical equation:
___AgI + ___Fe2(CO3)3 --> ___FeI3 + ___Ag2CO3
6AgI + Fe2(CO3)3 --> 2FeI3 + 3Ag2CO3
Jodie says that when she brewed coffee this morning, the water turned brown so it was an example of a chemical change. Explain why she is incorrect by justifying your answer with the evidences of physical change
Jodie is incorrect because the colour change is not a permanent colour change but occured as a result of the coffee mixing and dissolving into the water. This is an example of a physical change and is rreversible.
Bethany claims that frying an egg is a physical change. Justify whether she is correct or not.
Bethany is INCORRECT because there is a permanent colour change from clear to white and a gas is produced which can be observed in the smell of eggs cooking. It is also an irreversible change
Carbon dioxide and water react in the presence of sunlight to produce glucose and oxygen.
Identify the condition.
Presence of sunlight
Write the word equation. Include states
During photosynthesis, oxygen and soluble glucose are formed from carbon dioxide and water reacting in the presence of sunlight.
carbon dioxide(g) + water(l) ----> glucose(aq) + oxygen(g)
*condition = sunlight
**bonus: remember that chlorophyll is also a condition that is needed
Write a balanced chemical equation including states.
Magnesium (Mg) metal and hydrochloric acid (HCl) react to form magnesium chloride (MgCl2) solution and hydrogen (H2)
Mg(s) + 2HCl(aq) --> MgCl2(aq) + H2(g)