 Lv 1115 points

# Sean

• ### A cylindrical bar of gold that is 1.5 in high and 0.25 in in diameter has a mass of 23.1984 g, as determined on an analytical balance.?

An empty graduated cylinder is weighed on a triple beam balance and has a mass of 73.47 g. After pouring a small amount of liquid into the graduated cylinder, the mass is 79.16 g. When the gold cylinder is placed in the graduated cylinder (the liquid covers the top of the gold cylinder), the volume indicated on the graduated cylinder is 8.5 mL. Assume that the temperatures of the gold bar and the liquid are 86°F. What is the density of the gold at 30°C? What is the density of the liquid at 86°F? What is the density of the liquid at 300 K?

• ### According to the following reaction, ?

how many moles of O2(g) are needed to react completely with 112.0 L of CH4(g) at STP to produce CO2(g) and H2O(g)?

Chemistry2 months ago
• ### Help me with these questions please?

1. Aspirin (C9H8O4) is an acid which can be titrated with a base to determine purity. If an aspirin tablet weighing 1.83 g is titrated with standardized 0.2158 M KOH, the endpoint is reached after 24.42 mL of KOH has been added. What is the percent aspirin in the tablet?

89.5%

87.4%

86.8%

51.8%

2. If solutions of Co(NO3)3 and Mg(ClO3)2 are mixed, how many precipitation reactions will occur?

1

0

2

3

3. What is the molar solubility of BaF2 in 0.12 M NaF(aq) at 25 °C? The value of Ksp for BaF2 is 1.8 × 10–7 at 25 °C.

1.3 × 10–7 mol/L

1.3 × 10–5 mol/L

1.5 × 10–6 mol/L

1.2 × 10–3 mol/L

4. The solubility of Ag2CrO4 in water is 20.9 mg in 1.0 L of water at 25 °C. What is the value of Ksp for Ag2CrO4?

2.5 × 10–4

1 × 10–12

1 × 10–4

2.5 × 10–13

5. What is the solubility in mol/L of lead iodide, PbI2? Its Ksp value is 8.4 × 10–9.

2.0 × 10–3

1.3 × 10–3

9.3 × 10–27

1.6 × 10–3

6. Find the molarity of a copper (II) ion solution (Cu2+) if it requires 30.8 mL of 0.267 M S2– solution to reach an equivalence point with 35.6 mL of the copper (II) ion solution.

0.309 M

0.116 M

0.231 M

0.462 M

• ### If doubling the concentration of a reactant does not change the rate of the reaction, ?

the concentration of the reactant appears in the rate law with a(n)

• ### Determine the boiling point of a solution of 91.7 g of CoSO4 in 120 g of H2O. The solute ionizes according to the equation:?

CoSO4 → Co2+ + SO42–

• ### The fermentation of glucose to produce ethyl alcohol may be represented by the unbalanced equation:?

C6H12O6 → C2H5OH + CO2

Determine the grams of glucose (C6H12O6) required to produce 400 mL of 2.25 M ethyl alcohol (C2H5OH).

• ### If 24.0 grams of KOH react with 18.0 grams of (NH4)2SO4 according to the reaction below, ?

calculate the liters of NH3 produced at standard temperature and pressure.

2KOH + (NH4)2SO4 → K2SO4 + 2NH3 + 2H2O (already balanced)

• ### If 50 mL of 0.132 M permanganate solution are required to reach the equivalence point in a titration with 38 mL of iron (II) ion solution,?

what is the molarity of the iron (II) solution?

Iron (II) ion reacts with permanganate ion in the following balanced redox equation in acid solution.

8H+ + 5Fe2+ + MnO4– → 5Fe3+ + Mn2+ + 4H2O

• ### The table shown gives the solubility product constant (Ksp) for a few salts of mercury. ?

From the table, which saturated solution has the greatest value for [Hg+]?

Salt        Ksp

Hg2Br2  6 × 10–23

Hg2F2   3.1 × 10–6

Hg2Cl2  1 × 10–18

Hg2I2     5 × 10–29