Need help with my chemistry homework - who's game?
HL also solve problem 1+2 page 200 in the red book!
PART 1. NAME:_______________________________...
(from M97 and N97 SL)
1. How many grams of pure carbon are present in 11.5 g of ethanol, C2H5OH (Mr=46)?
2. The complete combustion of 1 mole of an unknown hydrocarbon yields 3 moles of carbon dioxide and 4 moles of water. What is the molecular formula of the hydrocarbon?
3. Aluminium powder reacts with hydrochloric acid according to the equation:
How many moles of hydrogen gas will be produced when 0.81 g of Al (Mr=27) is reacted with 0.12 dm3 of 0.40 M HCl?
4. Gallium consist of only two isotopes (69Ga and 71Ga) and has a relative atomic mass of 69.72
What conclusion can be drawn about the relative abundance of the two isotopes?
Ga-69 and Ga-71 are equal in abundance.
Ga-69 is more abundant than Ga-71.
Ga-69 is less abundant than Ga-71.
The relative abundance of these two isotopes can not be determined.
5. The formulae for the Nitrate ion is
6. What is the total number of s electrons in a nickel atom (atomic number 28)?
7. How many protons are present in the species with the symbol
8. Three elements; X, Y and Z, have atomic numbers n, n+1, n+2 respectively. X forms stable X- ions and Z forms stable Z+ ions. Which one of the following statements is correct?
X, Y and Z are all members of the same period of the Period Table.
X, Y and Z are all likely to be monatomic as elements
Y is likely to react with X
X- is likely to be larger than Z+
9. In which one of the following pairs are both substances ionic?
10. Which one of the following molecules contains 1 and 5 bonds?
ethanoic acid, CH3COOH
11. Which one of the following compounds is non-polar?
12. When the temperature of a fixed mass and volume of nitrogen is raised from 25oC to 50oC, the pressure increases because the
number of molecules increases
molecules expand and occupy greater volume
molecules collide more frequently and energetically with the surface of the container
molecules dissociate into separate ions
13. Ammonium nitrate is used in ´cold packs´ because it causes a decrease in temperature when it is dissolved in water. Whet is the enthalpy change for the dissolving process and the sign of ?
The process is endothermic and the sign of is +
The process is endothermic and the sign of is -
The process is exothermic and the sign of is +
The process is exothermic and the sign of is –
14. Water at temperature of 60.0oC is mixed in a 3:1 ratio with water at a temperature of 20oC. What is the temperature of the resulting water?
15. The decomposition of CaCO3 occurs via the equation:
For a system already at equilibrium, which of the following changes will produce more CO2?
Removing some of the CaO
Dividing the CaCO3 more finely
Increasing the temperature
Increasing the pressure
16. The HCH bond angle in ethane, H3CCH3, is closest to
17. The ClNCl bond angle in nitrogen trichloride, NCl3 is closest to
18. How many atoms are present in 0.10 mole of C3H4 ?
19. The balanced equation for the reaction of BaCl2 with Na3PO4 is
How many moles of NaCl could be produced from 2 moles of BaCl2 and excess Na3PO4 ?
20. All of the following affect the ionisation energy of an atom except the
mass of the atom
charge on the nucleus
size of the atom
main energy level from which the electron is removed
21. Which one of the following molecules contain a triple bond
a. Calculate the amount of substance of 3,00 g of Mg(OH)2
-Show your working!!
b. Calculate the mass of CuSO45H2O needed to produce 240 cm3 of a 0,12 moldm-3 CuSO4 solution.
-Show your working!!
2. Balance the following reactions:
47 cm3 of a solution containing Ca2+ ions is titrated using a solution containing 0,100 moldm-3 OH-. The reaction is:
Calculate the concentration of Ca2+ ions in the solution if 27 cm3 of OH- solution is used before the point of equivalence is reached.
List the following ions in order of increasing charge density: Co2+, Fe2+, Mn2+, Be2+, Cu+
-Explain how it is done.
Name the following ions:
NH4+ SO32- SO42- S2- HSO3- NO2- ClO4-