5. Compound X is composed of 52.2% carbon, 13.0% hydrogen, and the rest oxygen, by mass. The following quantity of X will contain 7.20 g of carbon. A. 3.76 g of X B. 7.20 g X C. 11.0 g of X D. 13.8 g of X E. Cannot calculate this, since the chemical formula of the compound is not provided.

Answer all the questions.

6 What is the mass of 2.0 billion billion atoms of gold? (1 billion is 1 x 10^9, so a billion billion is 1 x 10^18, so 2.0 billion billion is 2.0 x 10^18 atoms gold). O a. 0.00065 g O b. 0.83 g O c. 0.00033g O d. 3.9 x 10^20 g O e. 0.65 g O f. 3.3 g O g. 0.33 g O h. 0.065 g O i. 1.2 x 10^42 g Oj. O k. 6.5 g O. 3.3 x 10^-6 g none of these O m. 0.033 g

What amount (moles) is represented by each of these samples? a. 102.9 g Fe2O3 mol b. 34.6 mg NO2 mol c. 6.1 x 1016 molecules of BF3 mol

3. A mixture of Calcium carbonate and ammonium carbonate is 61.9% carbonate by mass. Find the mass percent of calcium carbonate in the mixture.

4. The Russian Space Agency uses potassium superoxide (KO2) for the chemical oxygen generators in their space suits. 4KO2 +2H2O+4CO2 -4KHCO3 +302 Complete the following table Mass of O2 Mass of H20 Mass of CO2 Mass of Mass of KO2 KHCO3 380 g ? ? ?

Calculate the empirical formula of each compound from the percent composition. Part A. 5.13 g of Cr and 2.37 g of O Part B. 2.82 g of K, 0.870 g of C, and 2.31 g of O Part C. 61.0% Sn and 39.0% F Part D. 56.3% P and 43.7% O Express your answer as a chemical formula.

b. If 1.530 g of copper (II) chloride reacts completely with 5.210 g of sodium carbonate, how much copper (II) carbonate can be formed when reaction completed?

Calculate the mass of Na in 80.0 g NaCl.A. 31.5 gB. 6.2 gC. 40.0 gD. 1.9 g

A molecule is found to contain 50.0% by mass C, 5.61% by mass H, and 44.4% by mass O. What is the empirical formula for this molecule? H. C.