Question

3. Given that a cup of coffee costs 90 cents and you have 100 grams each of nickels, quarters and dimes, if a nickel weighs 5.00 g, a quarter weighs 5.55 g and a dime weighs 2.22 g a) (8 pts) What is the maximum number of cups of coffee can you buy with your change? b) (2 pts) How much money will you have left over? 4. (10 pts) The law of mass conservation is another fundamental law in chemistry. This law states that matter can neither be created nor destroyed, which means that in a chemical reaction where all of the reactant is converted into product, the mass of reactant that reacts must be exactly equal to the mass of product produced. Next week you are going to test the law of mass conservation. To do this you will need to design your own experiment. a) Consider the 2 precipitation reactions you have already studied this semester. b) Think about an experimental procedure that you can use next week. Remember that you are trying to collect data that can be used to illustrate the law of mass conservation c) Contemplate how you might visually represent this data in the form of a graph. (0) What are the variables that you might need to plot. (ii) How would your choice of graph illustrate the law of mass conservation.

Answer 1

3.

a)

1 nickel = 5.00 g

100 g of nickel = 100 g x 1 nickel/5.00 g = 20 nickels

Now,

1 nickel = 5 cents

Therefore, 20 nickels = 20 nickels x 5 cents/1 nickel = 100 cents

1 quarter = 5.55 g

100 g of quarter = 100 g x 1 quarter/5.55 g = 18 quarters

Now,

1 quarter = 25 cents

Therefore, 18 quarters = 18 nickels x 25 cents/1 quarter= 450 cents

1 dime = 2.22 g

100 g of dime = 100 g x 1 dime/2.22 g = 45 dimes

Now,

1 dime = 10 cents

Therefore, 45 dimes = 45 dimes x 10 cent/ 1 dime = 450 cents

Total cents = (100 + 450 + 450) = 1000 cents

Hence, the maximum cups of coffee can be bought = 1000 cents x 1 cup/90 cents = 11 cups

b)

Cost of 11 cups of coffee = 11 cups x 90 cents/1 cup = 990 cents

Therefore, the left over money = (1000 - 990) = 10 cents