Frage 1
Frage
What is the mass number of an element?
Frage 2
Frage
True or false? Isotopes of the same element have the same physical properties but different chemical properties.
Frage 3
Frage
Which isotope of hydrogen has 1 neutron?
Antworten
-
Protium
-
Deuterium
-
Tritium
Frage 4
Frage
What is the relative formula mass of a compound?
Antworten
-
The sum of the atomic masses of each element relative to C-12
-
The mass of the compound which it has decayed from
-
The mass of the compound in micrograms
Frage 5
Frage
True or false? A mole of a substance is the amount that contains Avogadro's constant number of particles - this can be simplified to the relative formula mass in grams.
Frage 6
Frage
What percentage of magnesium oxide is magnesium? (RAM of Mg = 24, RAM of O = 16, magnesium oxide = MgO)
Frage 7
Frage
True or false? The empirical formula of a substance is the simplest ratio of the elements within it.
Frage 8
Frage
What is the empirical formula of the hydrocarbon containing 75% carbon? (RAM of C = 12, RAM of H = 1)
Frage 9
Frage
What can we learn from the balanced symbol equation?
Antworten
-
Number of molecules involved in each side of the reaction
-
Number of moles involved in each side of the reaction
-
The rate of the reaction
-
How much energy is required to carry out the reaction
Frage 10
Frage
Given that H2 + Cl2 --> 2HCl, what mass of HCl would you expect to produce with 17.75g of Cl2? (RAM of H = 1, RAM of Cl = 35.5)
Frage 11
Frage
True or false? The formula to work out percentage yield is theoretical yield/actual yield * 100.
Frage 12
Frage
Given that CaCO3 --> CaO + CO2, what is the percentage yield of CaO if 100g of CaCO3 were used and 39g of CaO were collected? (RAM of Ca = 40, RAM of C = 12, RAM of O = 16)
Frage 13
Frage
Why is the percentage yield of a reaction rarely 100%?
Antworten
-
The reaction may be reversible
-
Some of the product may not be collected
-
The reaction may be incomplete
-
The product may have been hidden
Frage 14
Frage
What is a reversible reaction?
Antworten
-
One in which the reaction is always incomplete
-
One in which the products may react to produce reactants
-
One in which the products disintegrate upon production
Frage 15
Frage
Assuming that the reaction is reversible, what is the scientific notation for the reaction between ammonia and hydrogen chloride to form ammonium chloride?
Frage 16
Frage
True or false? One key application of chemical analysis is detection of illegal food additives such as tartrazine.
Frage 17
Frage
Which of these analytical methods does not rely on machinery?
Antworten
-
Mass spectrometry
-
Gas chromatography
-
Paper chromatography
Frage 18
Frage
Which of these are advantages of using instrumental methods of analysis?
Antworten
-
More expensive
-
Very accurate and sensitive
-
Quicker
-
Requires training to use
-
Can be used with small samples
-
Is only useful with known data to compare it to
Frage 19
Frage
What is measured to identify compounds in GC-MS?
Antworten
-
Molecular ion peak
-
Retention time
Frage 20
Frage
What separates out compounds in a mixture in GC-MS?
Antworten
-
Molecular ion peak
-
Retention time