Please help me. i tried solving and it always came out as wrong. Thanks Part A.

Question

Please help me. i tried solving and it always came out as wrong. Thanks

Part A. convert the following

1. 245 cal to kJ. Express the value in kilojoules to three significant figures.

2. 4.35×106 kJ to kcal. Express the value in kilocalories to three significant figures.

3. 4.45×103 kJ to kWh. Express the value in 2 sig figs

4. 7.04×104 J to Cal.

Part B

1. Find the mass in grams of 43.6 mol Xe. Express your answer using three significant figures.

2. 1.2 mol W. Express your answer using two significant figures

Explanation / Answer

Part A-

1.

1 cal = 4.4184 KJ

1 cal = .001 kcal

245 cal = 0.245 kcal

0.245 kcal = 1.025 KJ

2.

1 KJ = 0.238846

4.35 x 106KJ = 461.1 KJ = 110.131 kcal.

3.

1KJ = 0.0002778 KWh

458.35 KJ = 0.1273KWh

4.

1 J = 0.2389 cal

132.16 J = 174.913 cal

Part B-

1.

MW of Xe = 131.292

131.293 x 43.6 = 5724.37 gm.

2. I am not getting what exactly you want in this question.( 1.2 mol W ??)

Please can you explain this question in comments, I will answer you.

Thanks.

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