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. 30.0 g H2O at an unknown temperature is mixed with 27.0 g of water at 15.8oC in a coffee-cup calorimeter. If
the final temperature of the mixture is 29.1oC, what is the initial temperature of the water?
Compare the amount of heat given off by 1.40 mole of liquid water when it cools from 100.0 oC to 30.0 oC to
that given off when 1.40 mol of steam cools from 200.0 oC to 110.0 oC ( Cp H2O (l) = 4.184 j/g-oC , Cp H2O (g)
= 1.87 J/j-oC) . Explain your comparison
. If 35.0 g H2O at 22.7°C is combined with 65.0 g H2O at 87.5°C, what is the final temperature of the
mixture? The specific heat capacity of water is 4.184 J/g⋅°C.
A coffee-cup calorimeter contains 50.0 g of water at 60.51°C. A 12.4 g piece of graphite at 24.21°C is
placed in the calorimeter. The final temperature of the water and the carbon is 59.02°C. Calculate
the specific heat of carbon. The specific heat of water is 4.18 J/g⋅°C.
If 24.15 ml of sodium hydroxide were required in the titration of a 4.9651 g sample of dried reagent potassium biphthalate (KHC8H4O4), what would be the normality of sodium hydroxide?
For 2AB+C₂ → A₂+2BC, suppose AH = 100kJ, E₁-250kJ, and that the intermediate is A + C. Describe a potential energy process for this reaction. You do not need to use your reaction mechanism for this question.
A reaction has a rate constant of 7.3x10 M/s at 315 K and a frequency factor of 4.4x10 What is the activation energy of the reaction?
Report the results of the following arithmetic equations with the appropriate number of significant figures. Assume that all values are experimental.
(a) 1.1037 + 0.914 + 8.62 =
(b) 3.1994 * 10 ^ - 3 + 6.145 * 10 ^ - 1 + 0.00317 =
(c) (106.8)(21.4) =
(d) (1.447 * 10 ^ - 3)(8.19 * 10 ^ - 1) = (e) (4.18 * 10 ^ - 4) ^ 3 =
(F) 8.11/1.6 =
(g) (14.16 + 3.179 - 9.08)/(3.159 + 4.4) =
(h) log (3.162 * 10 ^ 4) =
3-10. An analysis of city drinking water for total hardness produced the following results (in ppm CaCO,): 228.3, 226.4, 226.9, 227.1, and 228.6. Calculate the following.
(a) mean
(c) range
(e) standard deviation
(b) median
(d) average deviation
3-12. If the true concentration of CaCO, in the drinking water described in Problem 3-10 is 225.9 ppm, calculate the absolute and parts per thousand error.
what is the mass of acetylene
