chemistry multiple choice questions (chem-4)

multiple choice questions in chemistry

Energy from glucose:Amount of drinking water to avoid energy storage in body

An athlete is given 100 g of Glucose (C_6 H_12 O_6) of energy equivalent to 1560 kJ. He utilises 50 % of this gained energy in the event. In order to avoid storage of energy in the body, calculate the mass of water he would need to perspire. The enthalpy of evaporation of water is 44 kJ/mole.

time needed for oxygen atoms to achieve steady-state concentration

Calculate the characteristic time for oxygen atoms to achieve a steady-state concentration at 50 km and 100 km, as predicted by the Chapman mechanism.

Mass of a reactant in an etching reaction in the production of printed circuit boards.

See the attachment for the full problem statement. Finding the mass of a reactant in an industrial equation: Cu(NH3)4Cl2(aq) + 4 NH3(aq) + Cu(s) --> 2 Cu(NH3)4Cl(aq)

ARCHAEOLOGICAL CHEMISTRY

Answer the following questions, showing calculations and equations where appropriate: 1. Your analytical technique directly and accurately measures the concentration of iron-54 in your samples. How would you calculate the total iron concentration from these concentrations? What if you wanted to know the iron-oxide concentrati ...continues

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1. You're working with pottery that is tempered with an extremely pure quartz sand (quartz is silica, SiO2). Assuming that the clay component in your sherds is about 15% silicon (Si), and the sherds themselves assay out to about 30% silicon, c ...continues

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1.Steponaitis, Blackman, and Neff (American Antiquity 61:555-572, 1996) use the following correction for bulk elemental concentrations measured in shell- tempered pottery: e' = (1000000*e)/(1000000-2.5Ca), where e' = corrected elemental concen ...continues

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1. Zircon grains are extremely resistant to chemical weathering and thus they tend to be ground down mechanically into very fine sand and silt particles. In light of this observation, what element(s) would you expect to see enriched in ceramic ...continues

Archaeological Chemistry

Answer the following questions, showing calculations and equations where appropriate: 1. You have a radiocarbon sample analyzed and find out that the sample has 60% of the modern level of radiocarbon. Calculate the radiocarbon age of the sample using (a) an assumed 5730-year half-life and (b) a 5568-year half-life.

finding expressions for the partial molar volumes at T and P

The molar volume (cm^3 mol^-1) of a binary liquid mixture at T and P is given by: V = 120x1 + 70x2 + (15x1 + 8x2)x1x2 (a) Find expressions for the partial molar volumes of species 1 and 2 at T and P. (e)Plot values of V, partial V1, and partial V2 calculated by the given equation for V and by the equations developed in (a) vs. ...continues