How many grams are in 4.35 x 1021 molecules of water (H2O). Show work!

Soda ash (sodium carbonate) is widely used in the manufacture of glass.  Prior to the environmental movement much of it was produced by the following reaction.   CaCO3 + 2 NaCl → Na2CO3 + CaCl2   Unfortunately, the byproduct calcium chloride is of little use and was dumped into rivers, creating a pollution problem.  As a result of the environmental movement, all of these plants closed.  Assume that 125g of calcium carbonate (100.09 g/mol) and 125 g of sodium chloride (58.44 g/mol) are allowed to react.   Determine how many grams of useful sodium carbonate (105.99 g/mol) will be produced.  How many grams of useless calcium chloride (110.98 g/mol) will be produced?  You should also determine how many grams of excess reactants are left (indicate which one is the limiting reactant)

A sample of 48.7 g of tetraphosphorous decoxide (P₁0₁0) reacts with 84.6 g of water to produce phosphoric acid (H₂PO4) according to the following balanced equation. PAO10 + 6H₂O4 H₂PO4 Determine the limiting reactant for the reaction. H₂O OH₂PO4 OP4010 Calculate the mass of H3PO4 produced in the reaction. mass of H₂PO4: g

[Tutorial: Limiting reactant stoichiometry] This question will walk you through the steps of calculating the mass of products produced based on your determination of the limiting reactant.   b) Step 2a: Use dimensional analysis to determine the theoretical yield of the product. Calculate the theoretical yield in grams Al₂O₃ from the complete reaction of 64.7 grams Al according to the following balanced chemical equation: 2 Al(s) + Fe₂O₃(s) → Al₂O₃(s) + 2 Fe(s) c) Calculate the theoretical yield in grams Al₂O₃ from the complete reaction of 201 grams Fe₂O₃ according to the following balanced chemical equation: 2 Al(s) + Fe₂O₃(s) → Al₂O₃(s) + 2 Fe(s) d) Which of the following substances is the limiting reactant? e) What is the mass in grams of the excess Fe₂O₃ remaining after the partial reaction of 201 g Fe₂O₃ with 64.7 g Al? Give your answer to three significant figures.

how did you get the numbers beside the balanced equations. such as 4 beside H2O and 2 beside N2.

If 31.0 g of MgSO4⋅7H2O is thoroughly heated, what mass of anhydrous magnesium sulfate will remain? Express your answer to three significant figures and include the appropriate units.

2. A mixture of KCr(SO4)2 and its hydrate KCr(SO4)2-12H₂O has a mass of 1.2843 g. After heating to drive off all the water, the mass is only 1.1079 g. What is the weight percentage of KCr(SO4)2-12H₂O in the original mixture? Report your answer to 4 significant figures. Molar masses: KCr(SO4)2 283.22 g/mol; KCr(SO4)2-12H₂O 499.40 g/mol.

10. Ferrocene, synthesized in 1951, was the first organic iron compound with Fe-C bonds. An understanding of the structure of ferrocene gave rise to new ideas about chemical bonding and led to the preparation of many useful compounds. In the combustion analysis of ferrocene, which contains only Fe, C, and H, a 0.9437 g sample produced 2.233 g of CO2 and 0.457 g of H₂O. What is the empirical formula of ferrocene.

Consider the following balanced equation. 3 Ag(s) + 4 HNO3(aq) → 3 AgNO3(aq) + NO(g) + 2 H2O(l) A student used 117.24 g of Ag and obtained 135.49 g of AgNO3, calculate the percent yield of AgNO3. Give your answer to the correct number of significant figures without unit. Molar mass of Ag: 107.87 g/mol Molar mass of HNO3: 63.01 g/mol Molar mass of AgNO3: 169.87 g/mol Molar mass of NO: 30.01 g/mol Molar mass of H2O: 18.02 g/mol

An amount (in grams) of nitrogen gas is reacted with excess hydrogen, according to the balanced reaction shown below.  If 104 g of NH3 is recovered, giving a percent yield of 42%, what was the mass of the nitrogen (in grams) that reacted?   N2 (g) + 3 H2 (g) -->  2 NH3 (g)   Report your answer as an integer, that is as a number with zero decimal places, and with no units.  Do NOT use scientific notation.