Prelaboratory Questions Name Laboratory Section 8. 1. Consider the following reaction: 2 N2O5 (g) 4 NO2 (g) + O2 (g) -> The initial concentration of N,O5 was 0.84 mol/L, and 35 minutes after initiating the reaction, all of the N,O5 has been consumed. a) Calculate the average rate of the reaction over this 35-minute time interval. k[N2O5]? based on the balanced b) Is it correct to assume that the rate law is Rate chemical equation? Briefly explain your answer. %3D c) Suppose the reaction rate is determined by simultaneously measuring the rate of decrease of NoOs concentration (-A[N2O5]/At) and the rate of increase of NO, concentration (A[NO,J/At). Which rate will be higher and by what factor? (continued on next page) 137

Lead metal can be extracted from a mineral called galena, which contains 86.6% lead by mass. A particular ore contains 68.5% galena by mass. If the lead can be extracted with 92.5% efficiency, what mass of ore is required to make a lead sphere with a 3.00 cm radius?

110.0 g of iron is heated to 92.7 degrees C and then place in a container of water at 22.3 degrees C. The final temperature of the water and iron is 26.3 C. What is the mass of water in the container, assuming that all the heat lost by the iron is gained by the water. (significant figures needed) thank you!

A graduated cylinder contains 31.0 mLmL of water. What is the new water level after 35.1 gg of silver metal is submerged in the water?

Calculate the kinetic energy of a 0.15kg baseball moving at a speed of 45.0ms. Round your answer to 2 significant digits.

A tank contains 0.152 lbm of H2 (Hydrogen) and has a volume of 13.6ft^3 at 44.5 Pisa. What is the temperature in Fahrenheit?

Part C to heat 30.9 g of copper from 122°C to 247 C Express your answer using three significant figures. | ΑΣΦ Submit Part D Request Answer WEG ? to heat 30.9 g of copper from 122° C to 247 °C Express your answer using three significant figures. ΨΗ ΑΣΦ J cal

The temperature of a  7.47  ×  102  g air sample (density = 1.25 g/L) was lowered, and the density increased to 1.89 g/L.  Calculate the  new volume of the air sample.

Water is leaking from a pipe at a rate of 0.379 mL per second. How fast is the water leaking in L/hr?

Suppose that 880 mL of water changes in temperature from 20.20°C to 31.3°C. What is qwater in kJ? (Assume that the density of water is 1.0 g/mL and that the heat capacity of water is 4.2 J/(g.°C). Report your answer to the appropriate number of significant figures in the first blank below and the correct units in the second blank below.