Round 7: Sodium chloride (NaCl) can be used to melt snow. How many moles of sodium chloride are in a 10kg bag?
171.1 mol
Oops!
Check
Okay!
Check
15
2NaN3(s) --> 3N2(g) + 2Na(s)
To inflate the air bag on the driverโs side of the car, 80.0g of N2 is required. What mass of NaN3 is needed to produce 80.0g of N2?
124 g
Oops!
Check
Okay!
Check
5
Round 1: Naturally occurring silver exists as two isotopes. From the table above, calculate the average atomic mass of silver.
107.9 u
Oops!
Check
Okay!
Check
boom
Lose 50 points!
Oops!
gift
Win 25 points!
Okay!
gift
Win 10 points!
Okay!
thief
Give points!
5
10
15
20
25
15
Round 16: A hydrate of zinc nitrate has the formula Zn(NO3)2*xH2O. If the mass of 1 mol of anhydrous zinc nitrate is 63.37% of the mass of 1 mol of hydrate, what is the value of x?
Zn(NO3)2*6H2O
Oops!
Check
Okay!
Check
10
Round 10: Calculate the mass percent of nitrogen in Sr(NO3)2.
13.24%
Oops!
Check
Okay!
Check
20
4C3H6(g) + 6NO(g) --> 4C3H3N(g) + 6H2O(g) + N2(g)
What is the limiting reagent when 126 g of C3H6 reacts with 175g of NO?
C3H6
Oops!
Check
Okay!
Check
baam
Lose 25 points!
Oops!
gift
Win 5 points!
Okay!
fairy
Take points!
5
10
15
20
25
baam
Lose 10 points!
Oops!
15
Round 13: Compound X contains 69.9% carbon, 6.86% hydrogen, and 23.3% oxygen. Determine the empirical formula of Compound X.
C12H14O3
Oops!
Check
Okay!
Check
15
Dinitrogen pentoxide is a white solid. When heated it decomposes to produce nitrogen dioxide and oxygen.
2N2O5(s) --> 4NO2(g) + O2(g)
How many grams of oxygen gas will be produced in this reaction when 2.34g of NO2 are made?
0.406 g
Oops!
Check
Okay!
Check
5
Round 5: Find the molar mass of K2Cr2O7 and Fe2(SO4)3.
K2Cr2O7 = 294.2 g/mol
Fe2(SO4)3 = 399.91 g/mol
Oops!
Check
Okay!
Check
10
Round 6: Which sample has the largest mass?
A) 5.00 mol of C
B) 1.50 mol of Cl2
C) 0.50 mol of C6H12O6
B) Cl2 has 106 g
Oops!
Check
Okay!
Check
10
Round 12: A compound consists of 17.6% hydrogen and 82.4% nitrogen. Determine the empirical formula of the compound.
NH3
Oops!
Check
Okay!
Check
20
Round 4: A sample of pure acetic acid CH3COOH contains 1.40 x 10^23 carbon atoms. How many moles of acetic acid are in the sample?
0.116 mol
Oops!
Check
Okay!
Check
20
The following reaction proceeds with an 89% yield.
C2H5OBr + NaOH --> C2H4O + NaBr + H2O
What mass of C2H4O can be obtained when 3.61 x 10^23 molecules of C2H5OBr react with excess sodium hydroxide?