Balancing Equations
How do you balance a Chemical Equation?
Write the unbalanced equation to show the reactants and products.
Write down how many atoms of each element there are on each side of the reaction arrow.
Add coefficients (the numbers in front of the formulas) so the number of atoms of each element is the same on both sides of the equation. It's easiest to balance the hydrogen and oxygen atoms last.
Indicate the state of matter of the reactants and products and check your work.
An Ionic bond is a reaction between what and what?
A reaction between a metal and nonmetal.
What is conservation of mass?
A covalent bond is a reaction between what and what?
A reaction between two nonmetals.
How many periods or rows are there on the periodic table?
A. 7
B. 8
C. 9
A. 7
Balance this equation. N2 + H2 → NH3
1 N2 + 3 H2 → 2 NH3
Does it transfer or share electrons?
Transfer of electrons.
Mg + HCl -> MgCl2 + H2
When the above equation is balanced, the coefficient for magnesium chloride is —
A 0
B 1
C 2
D 4
B 1
Does it transfer or share electrons?
Sharing of electrons.
What is the symbol for potassium on the periodic table?
A. P
B. Po
C. K
K
Balance this equation, KClO3 → KCl + O2
2 KClO3 → 2 KCl + 3 O2
Is it high or low polarity?
High polarity (contains both positive and negative charges)
If all the reactants in a chemical reaction are completely used, which of the following statements accurately describes the relationship between the reactants and the products?
F The products must have a different physical state than the reactants.
G The total mass of the reactants must equal the total mass of the products.
H The reactants must contain more complex molecules than the products do.
J The density of the reactants must equal the density of the products.
G
The total mass of the reactants must equal the total mass of the products.
Is it high or low polarity?
Low polarity (low opposite charges)
The rows on the periodic table are arranged so that ___ are on the right side and ___ are on the left side.
A. Nonmetals / metals
B. Metals / nonmetals
C. Metals / gases
A. Nonmetals / metals
Balance this equation, NaCl + F2 → NaF + Cl2
2 NaCl + 1F2 → 2NaF + 1Cl2
What is an ion?
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Can matter be created or destroyed?.
No, it is conserved
How do you draw a covalent bond?
Step 1: Add up the total valence electrons.
Step 2: Determine the central atom.
Step 3: Place non-central atoms around the central atom, and connect using lines to represent the bonds.
Step 4: Distribute remaining electrons around the non-central atoms for a full valence shell.
What is the most conductive metal on the periodic table?
A. Silver
B. Copper
C. Gold
A. Silver
Balance this equation, H2 + O2 → H2O
2 H2 + 1 O2 → 2 H2O
What is a cation.
Positively charged ions are called cations
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What does a covalent bond do?
By sharing their outermost electrons, atoms can fill up their outer electron shell and gain stability.
What is the main difference between the modern and earlier periodic table?
A. The earlier table organised elements by atomic weight, while the modern table organised elements by atomic number
B. The earlier table organised elements by atomic number, while the modern table organised elements by atomic weight
C. There are no major differences between two versions
A. The earlier table organised elements by atomic weight, while the modern table organised elements by atomic number