Help asap ..

A certain compound has the percent composition (by mass) 85.63% C and 14.37% H. The molar mass of the compound is 42.0 g/mol. Ca

AlekseyPX

Answer:

The molecular formula is C3H6

Explanation:

Step 1: Data given

Suppose the compound has a mass of 100 grams

The compound contains:

85.63 % C = 85.63 grams C

14.37 % H = 14.37 grams H

Molar mass C = 12.01 g/mol

Molar mass H = 1.01 g/mol

Step 2: Calculate moles

Moles = grams / molar mass

Moles C = 85.63 grams / 12.01 g/mol

Moles C = 7.130 moles

Moles H = 14.37 grams / 1.01 g/mol

Moles H = 14.2 moles

Step 3: Calculate the mol ratio

We divide by the smallest amount of moles

C: 7.130 moles / 7.130 moles = 1

H = 14.2 moles / 7.130 moles = 2

The empirical formula is CH2

The molar mass of CH2 = 14 g/mol

Step 4: Calculate molecular formula

We have to multiply the empirical formula by n

n = 42 / 14 = 3

n*(CH2) = C3H6

The molecular formula is C3H6

8 0

3 years ago

What rules should you follow when adding and subtracting? Check all that apply.

GaryK [48]

Answer:

The answer to this question would be:

2. The exponents need to be the same so the leading numbers can be added or subtracted.

3. The result has the same number of decimal places as the least precise number.

The exponent is the 10^x that used in scientific notation. .When adding 12.3* 10^5 with 34.56 * 10^4, you need to make the exponent same first. In this case, it would become 12.3* 10^5 + 3.456 * 10^5= 15.756* 10^5

The decimal place could be rounded up to the least precise number. I'm not sure with the significant figures but it seems to use the biggest one.

Explanation:

brainly.com/question/7413247

5 0

3 years ago

For every 5.00 mL of milk of magnesia there are 400. mg of magnesium hydroxide. How many mL of milk of magnesia do we need to ne

trasher [3.6K]

Mg(OH)2 + 2 HCl → MgCl2 + 2 H2O

(0.0500 L) x (0.500 mol/L HCl) x (1 mol Mg(OH)2 / 2 mol HCl) x (58.3197 g Mg(OH)2/mol) = 0.729 g = 729 mg Mg(OH)2

<span>(729 mg Mg(OH)2) x (5.00 mL / 400 mg) = 9.11 mL milk of magnesia</span>

7 0

3 years ago

Read 2 more answers

Select the statement(s) that describe how climate change ca

Len [333]

Answer:

I think b

Explanation:

I think b becuase I'd it increases it would cause for stuff I dont know i am bot good but a guess is worth a try

7 0

2 years ago

Match the separation techniques with the correct descriptions.

nordsb [41]

Answer:

Explanation:

1 = A

Sublimation is the process where by a sample is heated to pass through solid phase to gaseous phase without the intermittent liquid phase. Example of substance that sublime is camphor.

2 = D

Decantantion

5 = F

Filtration is the process a liquid from solid using a porous material. This technique requires a set up and a good porous material eg filter paper.

6 = B

This technique is to separate a mixture of solids by converting them from solid phase to gaseous phase since they sublime.

3 = deposition.

The answer isn't in the option but deposition is the process of substance in gaseous phase to change into solid state without passing through liquid phase. Deposition is the opposite of sublimation.

4 = E

4 0

3 years ago