Chemstry Homework?

[Luke1260]

Part A. Calculate the mass of water produced when 5.46g of butane reacts with excess oxygen.

Part B. Calculate the mass of butane needed to produce 97.2g of carbon dioxide.

Part C. At a distance of 41ft , an ionizing radiation source delivers 4.5rem of radiation. How close could you get to the source and still have no biological effects?

Part D. A nurse administered 5.00mL of a radioisotope solution that has an activity of 165mL . What total dose of the radioisotope did the patient receive?

[WyeDyed]

What does your coursework tell you that "excess" is?

[Luke1260]

This is all the imformation for part A and B : Butane, C_4H_10, reacts with oxygen, O_2, to form water, H_2O, and carbon dioxide, CO_2, as shown in the following chemical equation:
2C_4H_10(g)+13O_2 (g)=10H_2O(g)+8CO_2(g)
The coefficients in this equation represent mole ratios. Notice that the coefficient for water (10) is five times that of butane (2). Thus, the number of moles of water produced is five times the number of moles of butane that react.

Also, notice that the coefficient for butane (2) is one-fourth the coefficient of carbon dioxide (8). Thus, the number of moles of butane that react is one-fourth the number of moles of carbon dioxide that you produce.
But be careful! If you are given the mass of a compound, you must first convert to moles before applying these ratios.

[jomifl]

Part C looks like a trick question as there is no known lower limit for the effect of ionizing radiation. Safe limit is another matter.

[jomifl]

Part D Your units don't make sense, have you read them properly?

[Luke1260]

Yea skip question D