Chapter 5 Flashcards
Recall the formula of hydrochloric acid
HCl
Recall the formula of Ethanoic Acid
CH3COOH
Recall the formula of carbon dioxide
CO2
Recall the formula of Hydrogen
H2
Recall the formula of Water
H2O
Recall the formula of sodium chloride
NaCl
Recall the formula potassium chloride
KCl
Recall the formula of calcium carbonate
CaCO3
Recall the formula of sulfuric acid and nitric acid
H2SO4 and HNO3
Recall the formula of sodium hydroxide, potassium hydroxide and magnesium carbonate
NaOH, KOH, MgCO3
Recall the formula of Sodium Sulfate
Na2SO4
Recall the formulas of Potassium Sulfate, Magnesium Sulfate, Barium Sulfate
K2SO4
MgSO4
BaSO4
Recall the formulas of Lead(II) Nitrate and Lead iodide
Pb(NO3)2
Pbl2
Recall the formulas of potassium iodide and potassium nitrate
Kl
KNO3
Recall and use the relationship between molar mass, number of moles and mass
number of moles = mass ÷ molar mass
Recall that the relative atomic mass of an element…
IS the average mass of an atom of the element compared to the mass of 1/12th of an atom of carbon-12.
Calculate empirical formula of a compound
1) Write each elements symbol
2) write each mass in g
3) write each ar
4) find the number of moles
5) divide by the smallest number
6) check for whole numbers, write the formula
Convert volume in cm3 into dm3 or vice versa
Divide or multiply by a thousand
Recall and use the relationship between the amount in moles, concentration in mol/dm3 and volume in dm3
amount in moles = concentration × volume
concentration = amount in moles ÷ volume volume = amount in moles ÷ concentration.
Interpret information on food packaging about guideline daily amounts (GDA)
Figuring out percentages and amounts refer to page 177 for more Information
Interpret more complex food packaging information and its limitations
Sodium chloride- common salt
Sodium ions it contains are needed for transmitting nerve signals and muscular contraction.
All foods contain salt in varying amounts and most processed foods contain added salt.
Too much salt can cause health problems including high blood pressure, leading to an increased risk of heart disease. The GDA for an adult is 6g.
The percentage by mass of sodium in sodium chloride is 39.3%. However sodium ions can come from other sources in food, so this conversion may be inaccurate.
Sketch a pH titration curve for the titration of an acid or an alkali.
Acid to an alkali( high to low)
Alkali to an acid (low to high)
Explain the need for several consistent titre readings in titrations.
It is important that the titre is accurate, otherwise the calculated concentration will be wrong. A titration is repeated until several consistent titres are obtained. Any anomalous titres are ignored and the mean titre is obtained.
Describe the difference in colour change during a titration using a single indicator, such as litmus or phenolphthalein, compared to a mixed indicator, such as universal.
Phenolphthalein is pink in alkaline solutions and colourless in acidic solutions.
Litmus is blue in alkaline solutions and red in acidic solutions.
Universal indicator- the several different indicators changes colour over a different range of pH values. Red in acids and purple in alkalis