Module 1 Flashcards
When writing a chemical formula, which atom goes first?
The more metallic element.
Where are the metals found on the periodic table?
The left side.
What are the 3 rules for writing Ionic Formulae?
- Place the CATION before the ANION
- Balance the Charges
- Use subscripts to show the number of ions
What do Roman Numerals refer to when attached to chemical symbols?
The charge. (III) = 3+
When balancing charges would you use subscripts or coefficients?
Subscripts.
What are the steps for testing pH?
- Add sample to distilled water
- Gently dip glass stirring rod into solution
- Touch wet rod to universal indicator paper
- Compare colour with pH colour scale paper
What are the steps for observing thermal decomposition?
- Transfer sample to test/boiling tube
- Gently heat by waving blue flame of bunsen under tube
- Observe results
Name the following, referring to Copper (II) Nitrate.
Appearance
Solubility in water
Colour on universal indicator paper
Observation upon heating
Blue solid
Soluble - forms blue solution
Red
Turns to green liquid, then black precipitate and brown gas. Brown gas relights glowing splint.
Name the following, referring to Anhydrous magnesium Carbonate.
Appearance
Solubility in water
Colour on universal indicator paper
Observation upon heating
White solid
Appears Insoluble
Green
Colourless gas given off that forms white precipitate in limewater, making the limewater turn cloudy.
Name the following, referring to Magnesium Chloride.
Appearance
Solubility in water
Colour on universal indicator paper
White solid
Soluble - colourless
Green
Name the following, referring to Magnesium hydroxide.
Appearance
Solubility in water
Colour on universal indicator paper
White solid
Appears insoluble
Blue
Isotopes have different numbers of electrons. True or False?
False. Neutrons are different. (Different atomic mass)
What is the formula for Relative Isotopic Mass
(Sum of all [% abundance x isotopic mass]) / 100
Atoms from which 3 groups are able to easily become cations?
1, 2, 3
Atoms from which 3 groups are able to easily become anions?
5, 6, 7
What are the maximum amount of electrons possible at the following energy levels: n=1, n=2, n=3, n=4?
1 = 2e 2 = 8e 3 = 18e 4 = 32e
What trend in the periodic table applies to each period?
Each period number is the amount of electron shells the atom has.
What trend in the periodic table applies to each group?
Each group number refers to an atoms number of valence electrons.
What are the rules for Dot and Cross diagrams for ionic bonds?
(Always x 3)
(Never x 4)
Always:
Count the electrons
Ions should have full outer shells
Make sure that you put square brackets and charges
around ions
Never:
Show electron shells overlapping
Show ions being shared
Remove electrons from inner shell
Give metals a negative charge
Give the chemical formula and charge for the following:
Hydroxide Nitrate Sulfate Carbonate Ammonium
OH = 1- NO3 = 1- SO4 = 2- CO3 = 2- NH4 = 1+
What are the rules for Dot and Cross diagrams for Covalent bonds?
(Always x 2)
(Never x 3)
Always:
Show shells touching or overlapping at bond
Count final electrons to ensure each outer shell is full
Never:
Include a charge
Draw electron shells separated
Draw unpaired electrons in region of overlap
Give the 5 steps for writing Ionic formulae.
- Write the name of the compound.
- Work out charge for positive ion.
- Work out charge for negative ion.
- Rewrite symbols. Put brackets around compounds.
- Swap and drop top numbers from top atoms to bottom atoms.
What are the 5 steps for working out masses for Products and Reactants during reactions?
- Write the balanced equation
- Write down the given masses, underneath the equation above
- Find the Ar/Mr of each atom/molecule
- Divide given masses by Ar/Mr (Step 2 / Step 3)
- Treat these like ratios, and rearrange to find the unknowns. (Multiply top from one with bottom from other, then divide by final number to get unknown.)
Give 3 reasons why most reactions are not 100% complete.
- Not all reactants react
- Some reactant is lost in glassware during transfer
- Some other unwanted products may form
Why is it problematic in industry that most reactions are not 100% complete?
Because it yields less of the desired product - meaning less can be used/sold.
Harmful waste is often produced (like CO2), which may damage environment.
How can industry control chemical reactions to make faster production and more money?
By reducing waste products produced, and by increasing the rate of reaction turnover.
Give the calculation for Percentage Yield.
(Actual Yield x 100) / Theoretical Yield
