Grade 10 Chemistry - Balancing Chemical Equations Flashcards
Qualitative observation
Observations that can not be measured or expressed in numbers
Quantitative observation
Observations that are measured and can be expressed in numbers
Inference
A possible explanation of something you observe; an educated guess.
E.g. silver was formed on the wire. You are INFERING that it’s SILVER.
The 7 clues that chemical change has occured.
- New color appeared
- Gas formed
- New solid formed
- Change in pH (acidity)
- Change in tempurature
- Light/flames/heat being released
- Not easily reversible
Dissolving sugar in water = physical
Leaves composting = chemical
Good scientific vocab:
Clear/translucent/opaque/un-clear
Colorless/odorless
Liquid/solid/gas/precipitate/heat/light
Lustrous
Granulated/dissolved/combusted/viscous
cm/m/litre
red/green/blue/yellow/grey-white/black
E.g.
It got fizzy = BAD scientific vocab
A gas formed = GOOD scientific vocab
Law of Conservation of Mass
Total mass of reactants = total mass of products
What is a skeletal equation?
An equation with the chemical formulas and their subscripts, but that it not balanced
Word equation
The names of the products and reactants/
E.g.
iron + oxygen = iron (III) oxide
iron and oxygen form iron (III) oxide
Balanced chemical equation
A balanced skeletal equation (basically just a skeletal equation with coefficients)
E.g.
2Na + Cl2 –> 2NaCl
CH4 + 2O2 –> CO2 + 2H2O
Synthesis reaction
A + B –> C
Two elements or compounds combine to make one compound
Decomposition reaction
A –> B+ C
One reactant falls apart into two or more elements or compounds
*If the compound is more than binary, one of the product compounds will be given
Hydrocarbon
A compound (can be found in a combustion reaction) composed of H, C, and sometimes O
Combustion reaction
hydrocarbon + O2 –> CO2 + H2O
In a combustion reaction, a compound composed of H, C, (and sometimes O) reacts with O2.
Single displacement reaction
A + BC –> AC + B
One element replaces another. The reactants must be a element and a compound. The product will be a new element, and a new compound.
* This uses the activity series to see if a reaction will occur. If an element is higher up on the activity series, then it will swap with the other element, otherwise no reaction will occur and no element will swap.
Double displacement reaction
AB + CD –> AD + CB
Two elements replace each other. Reactants must be two IONIC compounds or ACIDS. These are usually aqueous solutions. Cations and anions switch.
