Evidence of Chemical Change
Bubbles forming during a reaction indicates what kind of chemical change?
Formation of a gas
These numbers are placed in front of formulas to balance equations
Coefficients
A + B -> AB
Synthesis/Formation
Ionic compounds are made of these two types of particles
Cation and anion
1 mole = this many particles
6.02×10^23
A reaction changes a solution from clear to black. What type of chemical change is this?
Colour change
This law explains why equations must be balanced
Law of Conservation of Mass
AB -> A + B
Decomposition
Molecular compounds are made of these types of elements
Non-metals
The molar mass of water (H₂O) is found by ____ the atomic masses of hydrogen and oxygen
Adding !
2 substances react and start to smell really funky, like rotten eggs. What chemical change is this?
Change in odour
Balance: Mg + HCl → MgCl₂ + H₂
1Mg + 2HCl → 1MgCl₂ + 1H₂
Identify the type of reaction: Zn + HCl → ZnCl₂ + H₂
Single replacement
Name Ca(OH)₂
Calcium hydroxide
Calculate the molar mass of CO₂
44.01 g/mol
A solid appears when mixing two substances
Formation of a precipitate
Balance the combustion: CH₄ + O₂ → CO₂ + H₂O
1CH₄ + 2O₂ → 1CO₂ + 2H₂O
Why is hydrocarbon combustion NOT single replacement?
Combustion always forms CO₂ and H₂O
Which one is ionic, molecular, and an acid? HBr(aq), MgCl₂(s), CO₂(g)
HBr(aq) - Acid
MgCl₂(s) - ionic
CO₂(g) - molecular
What is the molar mass of Al₂(SO₄)₃ ?
342.17 g/mol
A reaction that releases energy and feels warm indicates what kind of chemica change?
Exothermic/energy change
Why can't you change subscripts when balancing?
It changes the identity of the substance
Predict the products: AgNO₃ + KBr → ?
AgBr(s) + KNO₃(aq)
What is the correct chemical formula for chromium(III) phosphate
CrPO₄
How many molecules are in 1.84 moles of carbon dioxide?
1.11 x 10^24 molecules