Chemistry Questions & Answers

The mass of 3.45 moles of \( \mathrm{H}_{2} \mathrm{O} \) is: Give your answer to the hundredths place in g. Do not put units in the answer space. 1

The mass of 2.27 moles of Sr is: Give your answer to the hundredths place in g. Do not put units in the answer space.

Element A has a molar mass of 1.41 g , element D has a molar mass of 66.58 g , and element E has a molar mass of 2.09 g . What is the molar mass of the compound \( \mathrm{A}_{3} \mathrm{D}_{4} \mathrm{E}_{2} \) ? Give your answer to the hundredths place in \( \mathrm{g} / \mathrm{mol} \). Do not put units in the answer space.

Element \( X \) has a molar mass of 7.55 g and element Z has a molar mass of 4.91 g . What is the molar mass of the compound \( \mathrm{X}_{3} \mathrm{Z}_{3} \) ? Give your answer to the hundredths place in \( \mathrm{g} / \mathrm{mol} \). Do not put units in the answer space.

The molar mass of \( \mathrm{H}_{2} \mathrm{O} \) is: Give your answer in \( \mathrm{g} / \) mol to two decimal places. Do not put units in the answer space.

The molar mass of NaCl is: Give your answer in \( \mathrm{g} / \mathrm{mol} \) to two decimal places. Do not put units in the answer space.

The molar mass of \( \mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2} \) is: Give your answer in \( \mathrm{g} / \mathrm{mol}_{\text {s }} \) to two decimal places. Do not put units in the answer space.

\begin{tabular}{l|l|l}\hline magnesium chromate & soluble \\ \hline sodium phosphate & soluble \\ ammonium sulfide & soluble \end{tabular}

\( BaCl _ { 2 } + H _ { 2 } SO _ { 4 } \rightarrow BaSO _ { 4 } + HCl \)

A patient had been hiking and admitted to drinking unsanitized spring water while hiking. Testing revealed that microbiota where not a cause of the patient's illness. Chemical analysis of the water was done looking for heavy metal contamination of lead, mercury, and barium with the following results: When a sample of the water from the spring was treated with a sodium fluoride solution a white precipitate formed. When the remaining water from that sample was then treated with a sodium iodide solution a red precipitate formed. A second water sample from the spring was then treated with a sodium iodide solution and then the remaining water was treated with a sodium phosphate solution which did not cause a visible reaction. Which contaminants were present in the water? (Mark all that apply.) You may find this solubility table in the textbook helpful. (Scroll down a bit to find the table.) v lead \( \square \) mercury