# Chemistry URGENT

A student heated a hydrated salt sample with an initial mass of 4.8702 g, After the first heating, the mass had decreased to 3.0662 g (two part question)

1. if the sample was heated to constant weight after reheating, what is the minimum mass that the sample can have after the second weighing? Show how you determined your answer.
2. the student determined that the mass lost by the sample was 1.8053. what was the percent water in the original hydrated sample? show calculation setup.

I think #1 is 1.804 g i got this by subtracting 3.0662 g from 4.8702 g.

I think #2 is 1.8053/4.8702 x 100 = 37.07
Could someone let me know if I am understanding this and doing it correctly?

1. 👍 2
2. 👎 0
3. 👁 3,317
1. #2 is right.
#1 I'm unsure exactly what is being asked. I think I responded to this question within the last few days but I interpreted the question then as being one of accuracy/precision of weighing. I thought they were after the precision of balances et al. I don't know the answer to #1 (is this all of the question?); at any rate, 1.804 g is not right.
If the original mass was 4.8702 and the final mass after all of the H2O was gone is 1.8053, then the mass at constant weight can't be less than 4.8702-1.8053 = ?
Do have some hints to give for #1. What are you studying(statistics, weighings, balances?). What course is this?

1. 👍 1
2. 👎 0
2. Question number 1 is simply asking what the weight of the second heating needs to be in order for the compound to be "dehydrated." The two weights need to be within .05g in order for the sample to be dehydrated. In this case:
4.8702g(initial mass)- 3.0662(after first heating)= 1.804g
3.0662(mass after first heating)- .05g(maximum variance in mass in order to be dehydrated)= 3.0162g
Keep in mind the .05g variance is used in order to determine "constant weight."

1. 👍 1
2. 👎 0
3. Phil- so is the answer for #1 3.0162? What about the answer for#2, is 37.07% correct?

1. 👍 1
2. 👎 0
4. i think the answer is 1.358

1. 👍 1
2. 👎 0

## Similar Questions

1. ### Chemistry 11

A 5.0 g sample of Cu(NO3)2-nH20 is heated, and 3.9 g of the anhydrous salt remains. What is the value of n? I got as far as finding the molar mass of Cu(NO3)2, which is 187.5g/mol Please help me further with this question.

2. ### chemistry

a hydrated salt is a solid that includes water molecules within its crystal structure. a student heated a 9.10-gram sample of a hydrated salt to a constant mass of 5.41 grams. what percent by mass of water did the salt contain?

3. ### Chem

A 25.0 mL aliquot of a well-shaken and filtered sample of river is pipetted into an evaporating dish. The sample was heated to dryness. Assume the density of the river water was 1.01g/mL. The following data were collected for

4. ### AP Chemistry

(a)calculate the mass percent of carbon in the hydrated form of the solid that has the formula BeC2O4 X 3 H2O (s). I divided 24.02 g by 151.08 g and got .16, or 16%. is that correct? Also, I'm having trouble with this follow up

1. ### Chemistry

A 0.60 g sample consisting of only CaC2O4 & MgC2O4 is heated at 5000C, converting the two salts of CaCO3 and MgCO3 . The sample then weighs 0.465 g. If the sample had been heated to 9000C, where the products are CaO & MgO, what

2. ### Chem 11

So I did a lab determining the chemical formula of a hydrate. I really just need somebody to check this over for me. We had to find the molecular formula of a hydrate of copper (2) sulphate, CuSO4 .xH2O. My observation table looks

3. ### chemistry

Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 5.00-g sample is burned, and 2.50 g of CO2(g) is produced. What is the mass percentage of the table salt in the mixture

4. ### chemistry

mass of crucible- 26.4574g mass of crucible and hydrated sample- 27.7617g mass of hydrated sample 1.3043g mass of crucible and dehydrated sample- 27.5693g mass of dehydrated sample- 1.1119g mass of filter paper- 0.7089g mass of

1. ### chemistry

FORMULA OF A HYDRATE Some salts, when crystallized from water solutions, retain definite proportions of water as an integral part of the crystal structure. This type of crystal is called a hydrate. In this experiment, you will

2. ### Chemistry

An ionic hydrate has the formula Pb3(PO4)4 • xH2O. The total mass of the hydrated ionic compound is 18.3g. After analysis, it was found that the anhydrous compound had a mass of 17.36g. What is the complete formula for this

3. ### chemistry

If a student attempts to identify an unknown compound by methodused in this experiment. She finds that when she heated a sampleweighing 0.4862 g the mass went down appreciably, to 0.3067 g. Whenthe product was converted to

4. ### Chemistry

if some volatile impurities in the crucible are not burned off in step 1 but are removed in step 4 is the reported percent mass of water in the hydrated salt too high or too low?