Topic 5a Mass calculations, electrolysis, extraction of metals and equilibria Flashcards
- What is the formula of water?
H2O
- What is the formula of sodium chloride?
NaCl
- What is the formula of carbon dioxide?
CO2
- The formula of magnesium chloride is MgCl2. What is the ratio of magnesium ions to chloride ions?
1:2
- The formula of sulfuric acid is H2SO4. How many atoms of each element are in the formula?
H = 2, S = 1, O = 4
- The formula of calcium nitrate is Ca(NO3)2. How many calcium, nitrogen and oxygen atoms are in the formula?
Ca = 1, N = 2, O = 6
- There are two numbers alongside chlorine in the periodic table, 17 and 35.5. What does the number 17 represent?
atomic number
- What does the number 35.5 represent?
relative atomic mass
- Sodium chloride has the formula NaCl. The relative atomic mass of sodium is 23 and that of chlorine is 35.5. What is the relative formula mass of NaCl?
58.5
- A water molecule has the formula H2O. The relative atomic mass of hydrogen is 1 and that of oxygen is 16. What is the relative formula mass of a molecule of water?
18
- What is the symbol for relative atomic mass?
Ar or RAM
- What is the symbol for relative formula mass?
Mr or RFM
- The relative atomic mass of hydrogen is 1. What is the relative formula mass of hydrogen molecules?
2
- Sodium chloride has the formula NaCl; the relative atomic mass of sodium is 23 and that of chlorine is 35.5. What is the relative formula mass of NaCl?
58.5
- A water molecule has the formula H2O; the relative atomic mass of hydrogen is 1 and that of oxygen is 16. What is the relative formula mass of water?
18
- A carbon dioxide molecule has the formula CO2; the relative atomic mass of carbon is 12 and that of oxygen is 16. What is the relative formula mass of carbon dioxide?
44
- What is the empirical formula of a compound with molecular formula C2H4?
CH2
- What is the empirical formula of a compound with molecular formula C3H8?
C3H8
- A sample of magnesium carbonate was heated in an open test tube. Why did it lose mass?
gas/carbon dioxide escaped
- 100 cm3 of a solution contained 2 g of salt. What is the concentration of the salt in g dm-3?
20
- A sample of copper carbonate was heated in an open test tube. Why did it lose mass?
gas/carbon dioxide escaped
- Why does magnesium increase in mass when it is heated in air?
combines with oxygen
- How many cm3 are there in 1 dm3?
1000
- What is 250 cm3 expressed in dm3?
0.25
- What is 0.5 dm3 expressed in cm3?
500
- 100 cm3 of a solution contains 1.5 g of salt. What is the concentration of the salt solution in g dm3?
15
- 250 cm3 of a solution contains 5 g of sugar. What is the concentration of the sugar solution in g dm3?
20
- A solution of copper sulfate has concentration 10 g dm3. What mass of copper sulfate will be dissolved in 100 cm3 of solution?
1 g
- 2 g of hydrogen reacts with oxygen to form 18 g of water. What mass of water will be formed from 1 g of hydrogen?
9 g
- 2H2 + O2 → 2H2O. How many molecules of hydrogen are needed to react with 1 dozen molecules of oxygen to form water?
2 dozen
- What is the abbreviation used for the mole, the unit for amount of substance?
mol
- How many particles are there in 1 mole of particles?
6.02 x 1023
- The mass of 1 mole of carbon atoms is 12 g. What is the mass of 2 moles of carbon atoms?
24 g
- What is the formula for calculating the number of moles of substance from its mass in g
moles = mass (g) / RAM or RFM
- Each water molecule contains three atoms. How many moles of atoms are there in 2 moles of water molecules?
6 mol
- The relative formula mass of chlorine gas is 71. What is the mass of 1 mole of chlorine gas?
71 g
- What is the Avogadro number?
6.02 x 1023 the number of atoms/particles in a mole
- What is the emperical formula of a compound?
The simplist whole number ratio of atoms in compound
- What is the law of conservation of mass?
total mass of reactants = total mass of products
- How are the emperical formula and molecular formula related?
The molecular formula is a multiple of the emperical formula
- What name is given to an atom that has gained or lost electrons?
ion
- What type of charge is on metal and hydrogen ions?
positive
- What type of charge is on most non-metal ions?
negative
- What is another name for a positive ion?
cation
- What is another name for a negative ion?
anion
- What is the symbol for a sodium ion?
Na+
- What is the symbol for a magnesium ion?
Mg2+
- What is the symbol for a chloride ion?
Cl<span>-</span>
- What is the symbol for a sulfate ion?
SO42-
- In what states do ionic compounds conduct electricity?
when molten or dissolved in water
- Which of these is not an electrolyte: solid sodium chloride, molten sodium chloride, aqueous sodium chloride?
solid sodium chloride
- What is the name of the positively charged electrode?
anode
- What type of ions are attracted to the positively charged electrode?
anions / negative ions
- What is the name of the negatively charged electrode?
cathode
- What type of ions are attracted to the negatively charged electrode?
cations / positive ions
- H What process takes place when a substance gains electrons?
reduction
- H In terms of subatomic particles, what happens to a substance when it is oxidised?
It loses electrons.
- H What type of reaction takes place at the anode during electrolysis?
oxidation
- What are inert electrodes made from?
graphite / platinum
- What is produced at the cathode when molten lead bromide is electrolysed?
lead
- What gas is formed when sodium reacts with water?
hydrogen
- What solution is formed when sodium reacts with water?
sodium hydroxide
- What colour is universal indicator when added to sodium hydroxide?
blue or purple
- What gas is formed when magnesium is added to dilute sulfuric acid?
hydrogen (MASH)
- What solution is formed when magnesium reacts with dilute sulfuric acid?
magnesium sulfate
- What would you see when magnesium is added to dilute sulfuric acid?
effervescence/fizzing/bubbles/magnesium disappears
- Name a metal that does not react with water or dilute acids.
copper/silver/gold/platinum
- What products are formed when zinc is added to copper sulfate solution?
zinc sulfate and copper
- What type of reaction takes place when zinc is added to copper sulfate solution?
displacement
- Magnesium reacts with chromium nitrate solution to form magnesium nitrate and chromium. Which metal is more reactive?
magnesium
- Name a metal that reacts vigorously with cold water.
potassium/sodium/rubidium/caesium/lithium/calcium
- What gas is produced when a metal reacts with water?
hydrogen
- How do you test for the gas produced in question 2?
It pops a lighted splint.
- What type of solution is formed when a metal reacts with water - acidic, alkaline or neutral?
alkaline
- What salt is formed when zinc reacts with hydrochloric acid?
zinc chloride
- Complete the word equation, magnesium + copper sulfate makes …
copper + magnesium sulfate
- What type of ions are formed from metal atoms when they react with acids?
cations/positive ions
- What type of reaction takes place when a substance loses oxygen?
reduction
- Name a metal that occurs uncombined in the Earths crust.
gold/silver/platinum
- Name a metal that could be extracted from its metal oxide by heating with carbon.
zinc/iron/copper
- Name a metal that occurs uncombined in the Earths crust.
gold/silver/platinum
- Name a metal, other than iron, that could be extracted from its metal oxide by heating with carbon.
zinc/copper
- What compound of carbon is formed when it is heated with copper oxide?
carbon dioxide/carbon monoxide
- Why is electrolysis not used to extract iron from iron oxide?
too expensive/too much energy needed
- Why is aluminium not extracted by heating aluminium oxide with carbon?
aluminium is more reactive than carbon/carbon is not reactive enough to remove the oxygen
- What is the aluminium oxide dissolved in to form the electrolyte for electrolysis?
molten cryolite
- What are the electrodes made from?
carbon/graphite
- At which electrode is the aluminium produced?
cathode/negative electrode
- What type of reaction takes place when a metal is extracted from its ore?
reduction/redox
- What type of reaction takes place when a metal corrodes?
oxidation/redox
- What is the definition of oxidation, in terms of oxygen?
gain of oxygen
- H What is the definition of oxidation, in terms of electrons?
loss of electrons
- What type of reaction takes place when metals are extracted from their ores?
reduction/redox
- What is the specific name for the corrosion of iron?
rusting
- Which of these metals will corrode most quickly - iron, sodium, copper?
sodium
- Why does sodium corrode most quickly.
most reactive metal corrodes most quickly
- Which substance has been oxidised in this reaction - copper oxide + hydrogen → copper + water?
hydrogen
- Which substance has been reduced in in this reaction - copper oxide + hydrogen → copper + water?
copper oxide
- What name is given to a process that converts an unwanted product into a new, useful product?
recycling
- Name a type of substance that can be recycled.
metal, plastic, paper, cardboard, glass, etc.
- What can happen in a reversible reaction?
the products can reform the reactants
- What does the term equilibrium describe?
a position of balance
- What is the process used to make ammonia?
Haber Process
- What is the molecular formula of ammonia?
NH3
- What is the balanced symbol equation for making ammonia from Nitrogen (N2) and Hydrogen (H2)
N2 +3H2 → 2NH3
- Where does nitrogen come from for use in the Haber Process?
From the fractional distillation of air
- Where does Hydrogen come from for use in the Haber process?
From methane from crude oil
- What conditions of pressure are required to increase the yield of ammonia in the Haber Process?
High pressure (because there are more molecules on the LHS of the equation)
- The forward reaction is exothermic. What conditions of temperature are required to increase the yield of ammonia in the Haber Process?
Low temperature (The equilibrium will shit to try and produce heat)
- Theoretically, a high yield of ammonia is produce at low temperature and high pressure. Why is this not used in reality?
Low temperatue will result in a slow rate of reaction. High pressures are expensive and dangerous.