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Two equal resistors of 15 kΩ each are connected in series across a 120 V source. A voltmeter when connected across each read 48 V in each case. Determine the resistance of the voltmeter.
Question 9
Calculate the number of moles of NH3 present in 100 g of NH3
a. 0.170 mol
b. 5.87 mol
c. 17.0 mol
d. 100 mol
e. 1703 mol
Question 10
Calculate the mass percentage of hydrogen in methane, CH4
a. 0.062 %
b. 0.251 %
c. 6.28 %
d. 12.6 %
e. 25.1 %
Question 11
A compound which contains 0.0130 mol C, 0.390 mol H and 0.065 mol O. What is the empirical formula for this compound?
a. CHO
b. CH5O2
c. CH30O5
d. CH39O6
e. C2H60O10
Question 12
What is the empirical formula for a compound that contains 17.34 % hydrogen and 82.66 % carbon by mass?
a. CH
b. CH2
c. CH3
d. C2H5
e. C5H
Question 13
Consider the following information to answer questions 13-17 below:
The unbalanced reaction of magnesium with oxygen is:
Mg + O2 → MgO
The correct balanced reaction is:
a. Mg2 + O2 → 2MgO
b. 2Mg + ½ O2 → Mg2O
c. 2Mg + O2 → 2MgO
d. Mg + O2 → MgO2
e. None of the above
Question 5
Given then the following reactions below, which one involves neither oxidation nor reduction?
a. Cl2 + H2O → HCl + HOCl
b. 2Na + 2H2O → 2NaOH + H2
c. 3NO2 + H2O → 2HNO3 + NO
d. POCl3 + 3H2O → H3PO4 + 3HCl
e. 2H2O → 2H2 + O2
Question 6
Calculate the oxidation number of phosphorus in KH2PO4?
a. -6
b. -2
c. 0
d. +5
e. +6
Question 7
Reactions which cannot occur spontaneously are called:
a. exothermic
b. endothermic
c. all reactions can occur spontaneously
d. no reactions can occur spontaneously
e. both [a] and [b]
Question 8
Calculate the number of moles of hydrogen atoms in one mole of (NH4)2SO4.
a. 1
b. 2
c. 4
d. 8
e. 15
Question 1
By applying the solubility guidelines, state which of the following compounds will precipitate in water?
a. Cobalt (II) hydroxide.
b. Sodium nitrate.
c. Ammonium phosphate.
d. Potassium Chloride.
e. None of the above.
Question 2
Consider an acid-base reaction when Nitric acid is added to copper(II) hydroxide. What is the net ionic equation for this reaction?
a. H+(aq) + OH-(aq) → H2O(l)
b. 2H+(aq) + Cu(OH)2(s) → Cu2+(aq) + 2H2O(l)
c. 2HNO3(aq) +Cu(OH)2(s) → Cu(NO3)2(s) + 2H2O(l)
d. 2H+(aq) + 2NO3-(aq) + Cu2+(aq) + 2OH-(aq) → Cu(NO3)2(s) + 2H2O(l)
e. 2H+(aq) + 2NO3-(aq) + Cu2+(aq) + 2OH-(aq) → Cu2+(aq) + 2NO3-(aq) + 2H2O(l)
Question 3
In a certain reaction, element X was converted to X2-. In the reaction, X acts as
a. a precipitating agent
b. an acid
c. a base
d. a reducing agent
e. an oxidizing agent
Question 4
Identify the type of reagent that is required to convert N2H4 to N2?
a. acid
b. base
c. reducing agent
d. oxidizing agent
e. precipitating agent
1. If 1.3 L of 3.0M potassium hydroxide completely neutralizes 0.7 L of carbonic acid
(H2CO3), what is the concentration of the carbonic acid? 2KOH+H,CO, K,CO,+2H₂O
2. How many moles of HCl are present in 0.07 L of 6 M HCI? 3. I add 7 mL of 2 M NaOH to 50 mL of water. What is the new concentration?
Rates of Reactions-Le Chatlier's Principle
2KOH+H₂CO,→K.CO,+2H2O overall energy of reaction (AH)=-683.84 kJ/mol 1. Describe 2 ways you could increase the amount of products of this reaction at
equilibrium. 2. Describe 2 ways you could increase the amount of reactants of the reaction at
equilibrium.
The moon has a mass of 7.34 x 10²²kg and a radius of 1.74 x 10⁶ meters. If you have a mass of 66kg, how strong is the force between you and the moon?
A motorcycle begins driving from at rest position. It accelerates at 8 km/hr2 for 20 seconds, then travels at a steady speed for another 20 seconds, all in the same direction. How much distance has it covered since it started driving?
Express 700.1400.2100.2800.3500.42000 in terms of factorial
A student collects 25 mL of gas at 96 kPa. What volume would this gas
occupy at 101.325 kPa. There’s no change in temperature or mass.
Suppose in a dice game, the person who rolls two dice wins if his rolls results in a pair of numbers whose sum is 7 or 11. in how many ways can he or she win?
