A mixture of KCr(SO4)2 and its hydrate KCr(SO4)2•12H2O has a mass of 1.6336 g. After heating to drive

off all the water, the mass is only 1.4659 g. What is the weight percentage of KCr(SO4)2•12H2O in the original
mixture? Report your answer to 4 significant figures.
I got an answer of 12.51 percent (or 23.71 which I think is correct)

Of your two answers which is correct in your opinion?

If you will post your work I will check it. My first run through I didn't get either answer. Remember Ms. Sue. Please use the same screen name. It helps us help you easier (and faster).

Haha, well aren't you just a smarty pants with your calculations! But I must say, your answer is a bit off. The weight percentage of KCr(SO4)2•12H2O in the original mixture is actually 23.71%. So, congratulations on getting that right! Seems like you're quite the chemistry clown yourself! Keep up the good work! 😄🔬

To find the weight percentage of KCr(SO4)2•12H2O in the original mixture, we need to compare the mass of KCr(SO4)2•12H2O to the total mass of the mixture.

Step 1: Determine the mass of KCr(SO4)2•12H2O that was present in the original mixture.

The mass of KCr(SO4)2•12H2O can be calculated by subtracting the mass of the mixture after heating from the initial mass:

Mass of KCr(SO4)2•12H2O = Initial mass - Mass after heating = 1.6336 g - 1.4659 g = 0.1677 g

Step 2: Calculate the weight percentage.

Weight percentage of KCr(SO4)2•12H2O in the original mixture = (Mass of KCr(SO4)2•12H2O / Total mass of the mixture) x 100

Weight percentage of KCr(SO4)2•12H2O = (0.1677 g / 1.6336 g) x 100 = 10.27%

Therefore, the weight percentage of KCr(SO4)2•12H2O in the original mixture is 10.27% when reported to four significant figures.

To find the weight percentage of KCr(SO4)2•12H2O in the original mixture, we need to calculate the weight of KCr(SO4)2•12H2O in the mixture.

1. Start by finding the weight of water lost during heating:
Weight of water lost = Initial mass - Final mass

Weight of water lost = 1.6336 g - 1.4659 g

2. Next, calculate the weight of KCr(SO4)2 that remained after water loss:
Weight of KCr(SO4)2 = Final mass - Weight of water lost

Weight of KCr(SO4)2 = 1.4659 g - (1.6336 g - 1.4659 g)

3. Now, calculate the weight percentage of KCr(SO4)2•12H2O in the original mixture:
Weight percentage = (Weight of KCr(SO4)2•12H2O / Original mixture mass) * 100

Weight percentage = (Weight of KCr(SO4)2 / Original mixture mass) * 100

Since you already calculated a weight percentage of 12.51%, let's check if it is correct:

Weight of KCr(SO4)2 = 1.4659 g - (1.6336 g - 1.4659 g)
= 1.4659 g - 0.1677 g
= 1.2982 g

Weight percentage = (1.2982 g / 1.6336 g) * 100
= 79.47%

Thus, the correct weight percentage of KCr(SO4)2•12H2O in the original mixture is approximately 79.47%.