1) how many atoms are in a 12.0 g sample of carbon?

a. 1.74 * 10^23 atoms

b. 6.02 * 10^23 atoms

c. 1.04 * 10^24 atoms

d. 7.24 * 10^24 atoms

2) given the following chemical equation:

ag no3 (aq) + kl (aq) agl(s) + kno3 (aq)

how many grams of potassium iodide will produce 750 grams of silver iodide, when there is an excess of silver nitrate?

a. 235

b. 707g

c. 529.79 g

d. 301 g

3) what is the molecular formula of a compound that has an empirical formula of c2h5 and a molecular mass of 116 grams/mole?

a. c2h5

b. c4h10

c. c6h15

d. c8h20

4) boron reacts with oxygen gas to form boron oxide, as shown in the reaction below:

4b(s) + 3o2(g) > 2b2o3(s)

how many grams of boron are needed to completely react with 492 g of oxygen gas?

a. 225.5g

b. 102 g

c. 216 g

d. 432 g

5) sulfuric acid is used in large quantities in petroleum refining and metallurgy as well as in the manufacture of fertilizer. if an industrial process requires 4.90 grams of h2so4, how many molecules are in this amount?

a. 7.00 * 10^20

b. 3.18 * 10^23

c. 6.02 * 10^23

d. 2.11 * 10^23

6) what is the mass of five mole of helium gas?

a. 2 g

b. 4 g

c. 8 g

d. 20 g

13. calculate the initial concentration (before precipitation) of carbonate ions after the addition of each 0.05 ml of solution b to the 1.00 l beaker of solution a. divide the work among group members and write the answers in the table in model 3. assume the volume change as solution b is added is negligible. 14. notice the initial concentrations of zn2+ - and cu2+ in the table in model 3. a. explain how these were obtained from the data in model 2. b. as solution b is added and precipitates form, do these initial concentrations change? 15. use the data in model 2 to indicate the presence of precipitate (either znco3 or cuco3) after each 0.05 ml addition of solution b in model 3. 16. use the initial concentrations of carbonate ions and zinc ions to calculate the reaction quotient, qsp for the zinc carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3. 17. use the initial concentrations of carbonate ion and copper(ii) ions to calculate the qsp for the copper(ii) carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3.

Which of the following statements are incorrect?

Abaker touches a pie right after taking it out of the oven. which statement best explains why the pie feels hot?