Other Chemistry Answers

The human hemoglobin is a tetrameric protein of about 64.5 KDa, consisting of two a chains and two B-chains tightly bound.

a) Calculate the number of amino acids present in the a-chains

b) What is the length of each B-chain?

e) What is the sum of the length of the two a-chains?

d) Find the length of the tetrameric protein hemoglobin assuming its all an alpha helical structure.

Quantitative analysis student Kenny Duit analyzed an ore sample for its copper content and obtained a mean of 4.67% Cu for three measurements. How many additional measurements must Kenny make to obtain a mean that is five times more reliable?

Indicate which of the following are determinate and which are indeterminate errors.

(a) A hygroscopic sample is not dried in the oven prior to weighing.

(b) A buret reading of 28.43 ml. is written down as 28.34 ml..

(c) The bottom of the meniscus in a buret is estimated to be at the zero-milliliter mark but

in fact is very slightly below this mark.

(d) The liquid in a 10-ml. TD (to deliver) pipet is blown out by mouth.

(e) The rest point of a meter needle, oscillating due to some desktop vibration, is estimated incorrectly.

What is the implied absolute and relative uncertainty in each of the following experimental values?

(a) 16

(b) 2.037

(c) 1.00 * 10 ^ - 3

(d) 0.060714

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.