Silicon carbide or carborundum is a widely used ceramic material in car brakes and bullet-proof vests because of its hardness. Carborundum is found naturally in the mineral moissanite, but the demand for it exceeds the supply. For this reason it is generally synthesized in the laboratory. The reaction is: SiO2 + 3 C→SiC + 2 CO How many kg of silicon carbide can be formed by the reaction of 250.0 kg of sand (SiO2) with excess carbon?

There are two steps in the extraction of copper metal from chalcocite, a copper ore. In the first step, copper(I) sulfide and oxygen react to form copper(I) oxide and sulfur dioxide: →+2Cu2Ss  3O2g + 2Cu2Os  2SO2g In the second step, copper(I) oxide and carbon react to form copper and carbon monoxide: →+Cu2Os  Cs + 2Cus  COg Suppose the yield of the first step is 86.%  and the yield of the second step is  64.% . Calculate the mass of copper(I) sulfide required to make  2.0kg  of copper.   Be sure your answer has a unit symbol, if needed, and is rounded to the correct number of significant digits.

Pure magnesium metal is often found as ribbons and can easily burn in the presence of oxygen. When 3.51 g of magnesium ribbon burns with 8.71 g of oxygen, a bright, white light and a white, powdery product are formed. Enter the balanced chemical equation for this reaction. Be sure to include all physical states. equation: 2Mg(s) + O₂(g) - What is the limiting reactant? magnesium oxygen If the percent yield for the reaction is 82.3%, how many grams of product were formed? mass of product formed: 4.77 How many grams of the excess reactant remain? mass of excess reactant: 2MgO(s) 6.4 Incorrect g g

of 15 Chlorine gas can be prepared in the laboratory by the reaction of hydrochloric acid with manganese (IV) oxide. 4 HCl(aq) + MnO₂ (s)→ MnCl₂ (aq) + 2 H₂O(1) + Cl₂(g) A sample of 39.9 g MnO, is added to a solution containing 44.5 g HCI. B d > What is the limiting reactant? E HCI O MnO₂ What is the theoretical yield of Cl₂? theoretical yield: If the yield of the reaction is 86.1%, what is the actual yield of chlorine? D $ 4 I R C с F % 5 V T G MacBook Pro 6 7 I I Y H B - N 4 8 J I 1 M 9 K O < F H O L P command Question F { [ option 8 Cl₂ ? 1 delete

An aqueous solution of NaF and an aqueous solution of PbCl2 react. Predict what solid will form and balance the chemical equation. If 30.6 mL of NaF solution reacted completely with excess PbCl2 to produces 10.7 g of the precipitate. What is the molarity of the original NaF solution?

Which of the following is not a combination reaction?     2 Na (s) + I2 (g) → 2 NaI (aq)     CaO (s) + CO2 (g) → CaCO3 (s)     CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (l)     N2 (g) + 3 H2 (g) → 2 NH3 (aq)     PbCO3 (s) → PbO (s) + CO2 (g)

Consider the following balanced equation for the reaction of aluminum with sulfuric acid: 2Al(s) + 3H₂SO4(aq) →→→ Al₂(SO4)3(aq) + 3H₂(g) How many moles of H₂SO4 are required to react completely with 3.2 mol of Al

Hydrogen gas reduces carbon dioxide gas to form methane (CH4) gas and steam. Choose the correct balanced net ionic equation (simplest whole-number coefficients) for this reaction.

A sample of 0.60 g of carbon dioxide was obtained by heating 1.48 g of calcium carbonate. What is the percent yield for this reaction? CaCOj(s) —+ CaO(s) + CO,(s) % 405 Supporting Materials

What type of reaction is represent by the equation: C,H12 + 902 → 6CO2 + 6H20