CHEM 1110 test 1 – Fall 2008 copy 975 page 1
Answer the following questions on the answer sheet.
AKEC
N = 6.022 × 10 mol T = t + 273.15
23 –1
1) Calculate the density of a piece of metal that has a mass of 264 g and a volume of 29.7 mL.
4
2) Calculate the number of moles there are in 17.2 g of CH ?
4
3) How many molecules are there in 26.5 moles of CH ?
24 34
4) How many grams of Na PO are produced by reacting 3.63 g of NaOH with an excess of H PO ?
34 34 2
The reaction is: H PO + 3NaOH ! Na PO + 3H O
4
5) What is the percent Fe, P and O in the compound: FePO .
34 34
6) How many grams of Na PO are produced by reacting 2.29 g of NaOH with 2.06 g of H PO ?
34 34 2
The reaction is: H PO + 3NaOH ! Na PO + 3H O
7) Which of the following is a characteristic of a scientific theory?
A) A theory is always tentative.
B) A theory is never really useful for practical applications
C) Beyond the original proof, theories cannot be proven.
D) Beyond the original proof, theories cannot be proven.
E) A theory must eventually be proven to be valid.
8) Convert 10.5 mg to grams.
9) Give the answer to the following operation to the correct number of significant figures.
4.12 + 9.35
1.3141
10) How many protons and neutrons are there in the isotope K ?
41