6. Chemical Reactions & Quantities

The oxidation of chromium solid is represented by the following equation:

4 Cr (s) + 3 O₂ (g) → 2 Cr₂O₃ (s)

How many moles of chromium (III) oxide are produced when 34.69 g Cr reacts with excess oxygen gas? 

The reaction of potassium chlorate and sucrose is given below:

8 KClO₃ + C₁₂H₂₂O₁₁ → 8 KCl + 12 CO₂ + 11 H₂O

If 2.33 x 10^-7 formula units of potassium chlorate are reacted, how many grams of carbon dioxide will be produced? 

If the density of ethanol, CH₃CH₂OH, is 0.789 g/mL, how many milliliters of ethanol are needed to produce 4.8 g of H₂O in the following reaction?

CH₃CH₂OH (l) + 3 O₂ (g) → 3 H₂O (l) + 2 CO₂ (g)

How many moles of NiCl₂ can be formed in the reaction of 6.00 mol of Ni and 12.0 mol of HCl?

Ni(s) + HCl(aq) → NiCl₂(aq) + H₂(g)

Balance the following equation, and tell how many moles of nickel will react with 9.81 mol of hydrochloric acid.

Ni(s) + HCl(aq) → NiCl₂(aq) + H₂(g)

The following diagram represents the reaction of A₂(red spheres) with B₂(blue spheres):

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b. How many moles of product can be made from 1.0 mol of A₂? From 1.0 mol of B₂?

Titanium metal is obtained from the mineral rutile, TiO2. The process requires multiple steps, as shown in the following reactions:

TiO₂(s) + 2 Cl₂(g) + 2 C(s) → TiCl₄(s) + 2 CO(g)

TiCl₄(s) + 2 Mg(s) → Ti(s) + 2 MgCl₂(s)

a. Write mole ratios to show the relationship between the reactants and products for each reaction.

Titanium metal is obtained from the mineral rutile, TiO2. The process requires multiple steps, as shown in the following reactions:

TiO₂(s) + 2 Cl₂(g) + 2 C(s) → TiCl₄(s) + 2 CO(g)

TiCl₄(s) + 2 Mg(s) → Ti(s) + 2 MgCl₂(s)

c. How many kilograms of rutile are needed to produce 95 kg of Ti?

Titanium metal is obtained from the mineral rutile, TiO2. The process requires multiple steps, as shown in the following reactions:

TiO₂(s) + 2 Cl₂(g) + 2 C(s) → TiCl₄(s) + 2 CO(g)

TiCl₄(s) + 2 Mg(s) → Ti(s) + 2 MgCl₂(s)

b. How many moles of TiO2 are needed to form one mole of titanium?

The chemical reaction of hydrogen with oxygen produces water.

2 H₂(g) + O₂(g) → 2 H₂O(g)

c. How many moles of H₂O form when 2.5 moles of O₂ reacts?

When table sugar (sucrose, C₁₂H₂₂O₁₁) is heated, it decomposes to form C and H₂O.

b. How many grams of carbon are formed by the breakdown of 60.0 g of sucrose?

Although Cu is not sufficiently active to react with acids, it can be dissolved by concentrated nitric acid, which functions as an oxidizing agent according to the following equation:

Cu(s) + 4 HNO₃(aq) → Cu(NO₃)₂(aq) + 2 NO₂(g) + 2 H₂O(l)

b. Is 35.0 g of HNO3 sufficient to dissolve 5.00 g of copper?

Ethyl alcohol is formed by enzyme action on sugars and starches during fermentation.

C₆H₁₂O₆ → 2 CO₂ + 2 C₂H₆O

If the density of ethyl alcohol is 0.789 g/mL, how many quarts can be produced by the fermentation of 100.0 lb of sugar?