1. Write the formulas for the following compounds: Compound Copper (II) chloride Iron(II) sulphate Sodium sulphate Ammonium nitrate Sodium nitrite Potassium sulphate Magnesium phosphate Formula Compound Lithium acetate Manganese (IV) nitrate Potassium permanganate Iron (III) oxide Potassium sulphite Potassium hydrogen carbonate Sodium iodate Formula
2. Express the following numbers in scientific notation: a) 0.000000027 b) 356 c) 47 764 d) 0.096 3. Express the following numbers as decimals: a) 1.52 10-2 b) 7.78 10-8 4. Express the answers to the following calculations in scientific notation: a) 145.75 + (2.3 10-1) b) 79 500 / (2.5 102) 5. State the number of significant figure in each of the following numbers. a) …show more content…
A student takes an object with an accepted mass of 200.00 grams and masses it on his own balance. He records the mass of the object as 196.5 g. What is his percent error? 11. Carry out the following conversion of units: a) 275 cm3 to dm3 b) 750 ml to litre c) 25C to K d) 60 km hr1 to m s1 12. An average adult has 5.2 L of blood. What is the volume of blood in m3? 13. The density of silver is 1.05 104 kg/ m3. Convert the density to units of g/cm3. 14. Aluminum is a lightweight metal (density = 2.70 g/cm3) used in aircraft construction, high voltage transmission lines, beverage cans, and foils. What is its density in kg/m3? 15. The density of ammonia gas under certain conditions is 0.625 g/L. Calculate the density in g/cm3. 16. The standard enthalpy change for the combustion of hydrogen gas is -286 kJ per mole of hydrogen. How much heat is released when 1.000 litres of hydrogen gas at STP is burned? (at STP, the volume of 1 mol of any ideal gas is 22.414 liters) 17. The human body is 0.0040% iron. How many milligrams of iron does a 64 kg person contain? 18. How many H atoms are present in 23.6 g of urea (NH2)2CO, which is used as fertilizers? Given 1 mol of urea has a mass of 60.06 g. 19. Complete the table for some of the elements occurring naturally. Element Sodium Scandium Arsenic Gold Symbol Na Sc As Au 21 79 Proton number Nucleon number 23 Number of neutrons 12 24 42 118 79 Number of …show more content…
20
19 27
21. P+ and Q are isoelectronic with a) b) c)
State the nucleon number of the isotope X State the number of protons in P and Q Identity the element P and Q
22. Do you agree with the statements below? If yes, mark () and if no, mark () No. Statement a. b. c. d. e. f. g. Any element can have only 2 isotopes 2 isotopes of an element may not have the same proton number Most elements do not have isotopes Isoelectronic particles must have the same number of electrons. Isoelectronic particles must have the same number of protons also. An atom X receives 2 electrons, then it is represented in symbol as X2An atom W loses 4 electrons, then it is represented in symbol as W4+ Answer
23. (Challenging) When a neutron is added to the nucleus of an atom: a) the proton number is altered b) the nucleon number is changed c) the new atom is an isotope of the original atom 24. Calculate the relative molecular mass of the following compounds: a) b) c) d) HNO3 Na2CO3 KClO4 Al2(SO4)3
25. The element boron consists of two isotopes,
11 5 B is
10 11 5 B and 5 B .
Their masses, based on the
10 5 B