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WorksheetsChemical Formulas, Equations and LOCM
Total questions: 11
Worksheet time: 6mins
Which of the chemical formulas below has the most atoms?
Zn(NO3)2
NaHCO3
CH3COCH3
H3PO4
Hydrogen (H2) reacts with oxygen (O2) to yield water (H2O). Which chemical equation below illustrates this reaction as a balanced equation?
2H2 + O2 => 2H2O
H2 + O2 => H2O
H2 + 2O2 => 2H2O
2H2 + 2O2 => 2H2O
In a lab investigation students took two identical beakers with a mass of 20 grams each and pour a liquid into each beaker. The total mass of the beakers and the reacting liquids was 50 grams. When the reactants were mixed together a blue color resulted, A chemical reaction produced a new product. If there was no gas produced and the mass was conserved, what is the total mass of the product and one beaker?
40 grams
30 grams
20 grams
70 grams
A chemical reaction is shown below.
2NaCl + 2H2O => Cl2 + H2 + 2NaOH
Which substance is a reactant?
NaCl
Cl
H2
NaOH
How many elements are in the chemical formula below?
CH3COCH3
10
6
3
1
How many atoms are in the chemical formula below?
Mg3(PO4)2
12
8
13
16
In the chemical reaction below 50 g of potassium (K) reacted with and unknown amount of oxygen (O2) to produce 75 g of Potassium superoxide (KO2). Ho much oxygen was used in this reaction according to the Law of Conservation of Mass?
O2 + K => KO2
125 grams
75 grams
25 grams
50 grams
In a chemical reaction, according to the Law of Conservation of mass, mass is not created nor destroyed. This means that.....
The mass of the reactants stays the same before and after the reaction has occurred.
The mass of the products stay the same before and after the reaction has occurred,
The mass of the products is doubled the mass of the reactants.
The mass before and after the reaction is the same.
Look at the chemical reaction below.
CH4 + 2O2 => CO2 + 2H2O
There are reactants on the left of the reaction and products on the right. If you count the atoms in the reactants, there are ...
4 carbons atoms, 4 hydrogen atoms, and 2 oxygen atoms
1 carbon atom, 4 hydrogen atoms, and 2 oxygen atoms
1 carbon atom, 4 hydrogen atoms, and 4 oxygen atoms
4 carbon atoms, 4 hydrogen atoms, and 4 oxygen atoms
What do the formation of rust and cottage cheese have in common?
Both involve chemical reactions
Both occur very quickly
Both are physical processes
Both are changes in state
Vinegar is added to baking soda and bubbles of carbon dioxide rapidly form leaving a cloudy liquid behind. What evidence shows a chemical change took place?
There is no evidence a chemical change took place.
A precipitant formed
A color change occurred
The formation of a gas
