# #49-62

label Chemistry
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Dec 8th, 2014

49

a) Ammonium Carbonate

b) Iron Nitrate

50

a) Mg(NO₃)₂

b) CaC₂

51.  30 atoms of oxygen

53.

a) Fe2O3 + CO  ----> 2FeO + CO2

b) Ca + Br2-----> CaBr2

c) (NH4)2CO3 => 2NH3 + CO2 + H2O

d) Na + H2O ===> NaOH + ½ H2

54. By definition, aa mole of any substance contains the same number of elementary particles as there are atoms in exactly 12 grams of the 12C isotope of carbon. Example: A single 12C atom has a mass of 12 amu, and a mole of these atoms would have a mass of 12 grams.

55. the number of atoms or molecules in one mole of a substance, equal to 6.023 × 1023.

56. There are 6.022 × 1023 atoms of potassium in every mole of potassium. Since one mole of KOH contains one mole of K, the answer is 6.022×1023 atoms of K.

57. That means one mole would be 32 grams.
So 16 grammes are:
16 / 32 = 0.5 mole sulfur

58. To calculate the molar mass of the compound, use the atomic weight values for each element on the periodic table. First, you need to count how many of each atom there are. There are 2 Carbon atoms, 6 Oxygen, and 1 Tin: Carbon weighs 12.01 amu; Oxygen weighs 16 amu; and Tin weighs 118.71 amu. Therefore, to get the total molar mass just add them all up:
(2*12.01) + (6*16) + (1*118.71) = 24.02 + 96 + 118.71 = 238.73 g/mol

Dec 8th, 2014

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Dec 8th, 2014
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Dec 8th, 2014
Nov 19th, 2017
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