posted by Diana
sorry! this is the full question:
Two samples of sodium chloride were decomposed into their constituent elements. One sample produced 1.78 g of sodium and 2.74 g of chlorine. Which of the following could be the results of the decomposition of the other sample, being consistent with the law of constant composition (also called the law of definite proportions or law of definite composition)?
i don't understand this at all.
I repeat that you didn't enter all of the problem. Where is the "which of the following could be the results of the decomposition of the other sample.......
a. 5.65 g of sodium and 1.42 g of chlorine
b. 5.65 g of sodium and 3.39 g of chlorine.
c. 5.65 g of sodium and 8.70 g of chlorine
d. 5.65 g of sodium and 12.4 g of chlorine
You can do this with a variety of ratios but I would pick (just to have a ratio greater than 1.0) Cl/Na. That is 2.74/1.78 = about 1.54.
Then go through the answers and find the Cl/Na ratio. The ratio that gives you 1.54 is the answer. For example, a is 1.42/5.64 = about 0.25 so a can't be right.
C is correct.
We should choose the answer whose approximation is the closest to our question.
Our question: 2.74/1.78 = 1.539325843
C = 8.70/5.65 = 1.539823009
The ratios between C and our question are very close.