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An oil rig pumps 30. barrels of oil/day, exactly. Each barrel holds 55.0 gallons

ID: 493547 • Letter: A

Question

An oil rig pumps 30. barrels of oil/day, exactly. Each barrel holds 55.0 gallons. If the density of the crude oil is 2.35 g/mL how long will it take the rig to produce 5.00 times 10^5 kg of oil? A new lab technician, on his first day on the job, drops his lab key into a large bottle of concentrated nitric acid, and key begins to dissolve. The mass of the key is 2.03 oz and has a density of 6.347 g/cm^3. The acid dissolves the key at a rate of 0.00235 g/s. By the time the lab tech gets the key out of the acid, 10.0 minutes have passed. What is the volume of the key remaining? A snail escapes from a French restaurant on foot. The snail can crawl exactly one inch in exactly 5 seconds. It has to crawl 12.03 km to get to the open countryside. After exactly 12 days, how far is the snail from the countryside? 58.752 g of aluminum pellets were added to 24.52 mL of water in a graduated cylinder. The water level rises to 46.28 mL. Calculate the density of the aluminum pellets.

Explanation / Answer

Ans. 8. Amount of oil pumped in 1 day = 30 barrels

                        = 30 x (55.0 gallons) = 1650 gallons         ; [1 barrel = 55.0 gallons]

                        = 1650 x (3.785 L) = 6245.25 L                   ; [1 gallon = 3.875 L]

                        = 6245250 mL                                              ; [1 L = 1000 mL]

                        = 6245250 mL x (2.35 g/ mL)                     ; [density is 2.35 g/ mL]

                        = 14676337.5 g

                        = 14676.3375 kg                                          ; [1 kg = 1000 g]

Thus, oil pumping rate = 14676.3375 kg/ day

Now,

Time required to produce 5.00 x 105 kg oil = (5.00 x 105 kg) / oil pumping rate

                                    (5.00 x 105 kg) / oil pumping rate

                                    = (5.00 x 105 kg) / (14676.3375 kg/ day)

                                    = 34.068 days         

Ans. 9. Mass of key = 2.03 oz

                                    = 2.03 x (28.38 g)                             ; [1 oz = 28.38 g]

                                    = 65.274 g

Rate of dissolution = 0.00235 g/s

Total mass dissolved in in 10 minutes = dissolution rate x time of dissolution

                                    = (0.00235 g/s) x 10 min

                                    = (0.00235 g/s) x 10 x 60 s              ; [1 min = 60 s]

                                    = 1.41 g

Remaining mass = Initial mass – Dissolved mass

                                    = 65.274 g – 1.41 g

= 63.864 g

Remaining volume of key = Remaining mass / density of key

                                    = 63.864 g / (6.347 g/ cm3)

                                    = 10.062 cm3

Ans. 10. Distance travelled by snail in 12 day = speed x time

                                    = (1 inch / 5 s) x 12 day

                                    = (2.54 inch/ 5s) x 12 day                            ; [1 inch = 2.54 cm]

                                    = (2.54 cm/ 5s) x 12 x 86400s                    ; [1 day = 86400 s]

                                    = 526694.4 cm

                                    = 5266.944 m                                               ; [1 m = 100 cm]

                                    = 5.26 km                                                     ; [1 km = 1000 m]

Distance from the countryside =

(distance between restaurant and countryside)- (distance travelled)  

= 12.03 km – 5.26 km

= 6.77 km

Ans. 11. Volume of Al = Increase in volume =

                        (Final water level – Initial water level)

                        = 46.28 mL – 24.52 mL = 21.76 mL

Mass of Al = 58.752 g

Density = Mass / Volume

                        = 58.752 g / 21.76 mL

                        = 2.76 g/ mL