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WorksheetsThe Ultimate Matter Challenge
Total questions: 10
Worksheet time: 50mins
Which of the following symbols represent the isotopic notation of Gallium-69?
31Ga
69
Ga31
69
69Ga
31
69G
31
Two naturally occurring isotopes of rubidium rubidium-85 and rubidium-87, which are found in the ratio 3:5. Determine the number of electrons in
85Rb+
37
36
48
37
85
A sample of 3.25 g compound, composing only titanium and chlorine is completely reduced by sodium metal to form 0.82 g titanium. Determine the empirical formula of that compound.
[Ar: Ti =48.0, Cl = 35.5]
TiCl
TiCl2
TiCl4
Ti2Cl
Definition of 10% NaOH by weight is
10 g of NaOH in 1L solution
40 g of NaOH in 100 g of solution
10 g of NaOH in 100 g of solution
40 g of NaOH in 1 kg of solution
What is the molality of 10.0 % by mass NaCl solution?
[Ar: Na = 23, Cl = 35.5]
1.70 m
1.00 m
10.00 m
1.90 m
What is the oxidation number of Cr in CrO4-2 ?
-2
+6
+3
+4
Choose the unbalanced equation from the following chemical equations
Mg + 2HCl --> MgCl2 + H2
2NO + 2CO --> N2 + 2CO2
3CCl4 + 2SbF3 --> 3CCl2F2 + 2SbCl3
4NO + O2 --> 4NO2
Potassium nitrate, KNO3, decomposes through heating as the equation below:
4KNO3 --> 2K2O + 2N2 + 5O2
What is the number of mole oxygen gas produced when if 0.25 mol of potassium nitrate decomposed?
5.00 mol
0.31 mol
0.20 mol
1.25 mol
Combustion of ammonia gas yields nitrogen monoxide and water vapour as equation below:
4NH3 + 5O2 --> 4NO + 6H2O
Determine the limiting reactant if 0.23 mol NH3 reacted with 0.35 mol O2
Ammonia
Oxygen
Nitrogen monoxide
water vapour
0.200 mol magnesium reacted with excess HCl as the equation below:
Mg + 2HCl --> MgCl2 + H2
Calculate the volume of hydrogen gas released at room condition.
0.20 L
4.48 L
4.80 L
0.45 L
