Chemical Reactions and Reaction Stoichiometry – Flashcards
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Phosphoric acid reacts with magnesium hydroxide to produce magnesium phosphate and water via the following reaction: ?H3PO4+?Mg(OH)2→?Mg3(PO4)2+?H2O Balance the equation and enter the coefficients.
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2,3,1,6
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You carefully weigh out 20.00 g of CaCO3 powder and add it to 81.00 g of HCl solution. You notice bubbles as a reaction takes place. You then weigh the resulting solution and find that it has a mass of 92.80 g . The relevant equation is CaCO3(s)+2HCl(aq)→H2O(l)+CO2(g)+CaCl2(aq) Assuming no other reactions take place, what mass of CO2 was produced in this reaction?
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8.20 g
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The unbalanced equation for the reaction between methane and bromine is: __CH4(g) + __Br2(l) → __CBr4(s) + __HBr(g) Once this equation is balanced what is the value of the coefficient in front of bromine Br2?
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4
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Write a balanced chemical equation for the reaction that occurs when calcium metal undergoes a combination reaction with O2(g).
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2Ca(s)+O2(g)→2CaO(s)
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Write a balanced chemical equation for the reaction that occurs when copper (II) hydroxide decomposes into copper (II) oxide and water when heated.
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Cu(OH)2(s)→CuO(s)+H2)(l)
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Write a balanced chemical equation for the reaction that occurs when heptane, C7H16(l) , burns in air.
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C7H16(l)+11O2(g)→7CO2(g)+8H2O(g)
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Write a balanced chemical equation for the reaction that occurs when the gasoline additive methyl tert-butyl ether, C5H12O(l), burns in air.
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2C5H12O(l)+15O2(g)→10CO2(g)+12H2O(g)
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A certain ionic compound is made entirely of aluminum and oxygen. What is the formula for this compound?
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Al2O3
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What is the mass percentage of each element in the compound Al2O3?
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% Al,% O = 52.9,47.1 %
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Which of the following is the correct formula weight for calcium phosphate?
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310.2 amu
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What is the chemical formula for quartz?
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SiO2
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How many oxygen atoms are in 2.10 g of quartz?
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4.21 x 10^22
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How many sulfur atoms are in 0.45 mol BaSO4?
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2.7 x 10^23
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How many sulfur atoms are in 1.10 mol of aluminum sulfide?
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1.99x 10^24
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The compound dioxane, which is used as a solvent in various industrial processes, is composed of C, H, and O atoms. Combustion of a 2.203-g sample of this compound produces 4.401 g CO2 and 1.802 g H2O. A separate experiment shows that it has a molar mass of 88.1 g/mol. Which of the following is the correct molecular formula for dioxane?
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C4H8O2
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A compound whose empirical formula is XF3 consists of 65 % F by mass. What is the atomic mass of X?
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31 g/mol
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How many moles of NH3 can be produced from 19.5 mol of H2 and excess N2?
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13.0 mol NH3
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How many grams of NH3 can be produced from 4.02 mol of N2 and excess H2?
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137 g NH3
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How many grams of H2 are needed to produce 12.40 g of NH3?
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2.202 g H2
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How many molecules (not moles) of NH3 are produced from 5.14×10−4 g of H2?
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1.02 x 10^20 molecules
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Calcium hydride reacts with water to form calcium hydroxide (aqueous) and hydrogen gas. Write a balanced chemical equation for the reaction.
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CaH2(s)+2H2O(l)→Ca(OH)2(aq)+2H2(g)
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How many grams of calcium hydride are needed to form 4.700 g of hydrogen gas?
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49.07 g
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When 24 mol of methanol and 15 mol of oxygen combine in the combustion reaction, 2 CH3OH(g) + 3 O2(g) → 2 CO2(g) + 4 H2O(g) what is the excess reactant and how many moles of it remain at the end of the reaction?
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14 mol CH3OH(g)
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1.13 g H2 is allowed to react with 9.89 g N2, producing 2.79 g NH3. What is the theoretical yield in grams for this reaction under the given conditions?
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6.37 g
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1.13 g H2 is allowed to react with 9.89 g N2, producing 2.79 g NH3. What is the percent yield for this reaction under the given conditions?
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43.8%
