Calculate the mass in grams of sodium sulfate trihydrate, if there are 3.4 moles of the compound.                                                  Na2SO4.3H20

calculate the number of molecules in 0.256 g of NH4Cl. (molar mass of NH4Cl = 53.492 g/mol; 1 mole = 6.02x10^23)

The max dose of sodium hydrogen phosphate (Na2HPO4)that should be taken in a day is 3.8 grams. How many moles is this? How many molecules? (you will need molar mass and Avagadro’s number).

Complete the table below for calculating the molar mass of the compound phosphorus triiodide. Molar mass of element Mass in one mole of phosphorus triiodide Moles g/mol mol %3D g g/mol x mol %3D Molar mass phosphorus triiodide = g/mol

4. The mass of silicon atoms is no. of Si atoms = 1.63x102 atom [Avogadro's O 1.04 x 10 g O 4.58 x 1022g O 2.71 x 10-25g O 7.60 x10-²g O 28.08 g

Calculate the number of moles of ethanol present in 243.3 mL of ethanol, CH3CH2OH, which has a density of 0.789 g/mL.

What is the mass in grams of 1.50 × 1025 molecules of 12?

A mineral sample is obtained from a region of the country that has high arsenic contamination. An elemental analysis yields the following elemental composition: Element Atomic Weight (g/mol) Percent Composition Co 58.9332 21.2% Fe 55.845 6.71% As 74.9216 72.0% What is the empirical formula of this mineral? CoFe3As8 CogFeAs3 Co3FeAs8 Co2FeAs8 O CoFeAs