Chemistry help

Question 1

An unknown salt solution was made in the stockroom using 150.0 grams of salt and 500.0 grams of water. Do the following problems based on this solution.

a) calculate the %NaCl and % water by weight
b) if you evaporated 88.840 grams of solution, what weight of salt should you get
c) If a student needed to recover 15.605 grams of salt, what weight of solution should the student take and evaporate.

Question 2

A student measured the width of his text with a cm ruler and with a hand. The student found that it is 21.6 cm or 2.10 "hands" wide. Write the conversion factors below

a) cm/hand
b) hand/cm
c) m/hand
d) what is the width of 5.0 hands in cm and m

Question 3

a small glass fish tank is 30. cm long, 15 cm high, 20. cm wide. Calculate the volume of water needed to fill it to the to in mL, cc, and L.

a) mL
b) cc
c) L

Question 3

an antacid tablet weighs 1.265 grams most of which is filler.  Each tablet contains 500. mg of active ingredient, calcium carbonate.

a) what is the percent by weight of calcium carbonate in each tablet
b) what weight of calcium carbonate is needed to make 25 tablets
c) how many tablets can be made from 15.0 grams of calcium carbonate?

Question 4

rust is a compound which is 70.7% iron, and the rest is oxygen

a) how many grams of iron, and how many grams of oxygen are there in 680 grams of rust?
b) how many grams of rust would contain 52.0 grms of iron

Question 5

an ore sample weighing 8.60 grams is found to contain 1.40 grams of copper

a) calculate the percent of copper in the ore
b) how many lbs. of copper are there in 2.00 tons of ore (1 ton=2000 lbs)
c) what weight of the ore (in lb.) would contain exactly 1.00 lb. of copper

Question 6

in an experiment 5.6 grams of magnesium combined with oxygen to form 9.3 grams of magnesium oxide.  Calculate the percent magnesium and the percent oxygen in the oxide formed.

Question 7

Show your method clearly; include correct units in answers. Note that density can be used as a conversion factor. If the density of a liquid is 1.23 g/mL, then the factors are: 1.23 g/l mL or 1 mL/1.23 g

a) use graph to read the weight of 5.8 mL of your unknown
(headings of graph mL of liquid, wt. of cylinder plus liquid, wt. of empty cylinder, grams of liquid and density)

b)a piece of metal weighs 44.867 g. When the metal is lowered into 25.0 mL of water in a graduated cylinder, the level rises to 28.5 mL. Calculate the density

c) which measurement, the weight or the volume, would be most likely to be inaccurate, giving error in the calculated density? Explain.

d) a solid cube, 2.2 cm on an edge weighed 6.488 grams. Will it sink or float in water? explain.

e) an oil has a density of 1.44 g/mL. How many mL are needed for 22.036 grams

f) how easy is it to toss around a brick of solid gold (Au) as they do in the movies? Calculate the weight in grams and pounds (1 lb. =454 g) of a gold brick 35.0 cm long with a square cross-section 9.5 cm by 9.5 cm. The density of gold is 19.3 g/cc