All categories

2 years ago

89.6 of H2O determine the number of moles

Chemistry

1 answer:

Katyanochek1 [597]2 years ago

5 0

Answer:

true ?

can you give me brainiest

You might be interested in

First person with the right answer gets brainliest thanks (btw the numbers on the right are the answers choose the right one)

kap26 [50]

Molar mass of FE2O3=2(55.85)+3(16)=159.7

2.56g*1mol/159.7*2mol/1mol*55.85g/1mol=1.79g

6 0

3 years ago

True or false when matter changes it’s state it is a physical change because it is the same substance the whole time.

Blababa [14]

Answer:

true

Explanation:

5 0

3 years ago

When a 0.245-g sample of benzoic acid is combusted in a bomb calorimeter, the temperature rises 1.643 ∘C . When a 0.260-g sample

sveticcg [70]

Answer:

The heat of combustion per moles of caffeine is 4220 kJ/mol

Explanation:

Step 1: Data given

⇒ When benzoic acid sample of 0.245 grams is burned the temperature rise is 1.643 °C

⇒ When 0.260 gram of caffeine is burned, the temperature rise is 1.436 °C

⇒ Heat of combustion of benzoic acid = 26.38 kJ/g

Step 2: Calculate the heat released: for combustion of benzoic acid

0.245 g benzoic acid * 26.38 kJ/g = 6.4631 kJ

Step 3: Calculate the heat capacity of the calorimeter:

c = Q/ΔT

Q = 6.4631 kJ / 1.643°C = 3.934 kJ/ °C

Step 4: Calculate moles of a 0.260 g sample of caffeine:

Moles caffeine = Mass caffeine / Molar mass caffeine

0.260 grams/ 194.19 g/mol = 0.0013389 moles

Step 5: Calculate heat released: for combustion of caffeine

Q = c * ΔT

Q = 3.934 kJ/°C * 1.436 °C = 5.65 kJ

Step 6: Calculate the heat of combustion per mole of caffeine

5.65 kJ / 0.0013389 moles = 4219.9 kJ/mol ≈ 4220 kJ/mol

The heat of combustion per moles of caffeine is 4220 kJ/mol

4 0

3 years ago

The effectiveness of a chemical sanitizer can be limited by

Serjik [45]

Chemical sanitizer effectiveness, decreases with increase in pH . And most soap and detergent are alkaline in nature, that limits its effectiveness. So they should be rinsed off completely for proper effectiveness of santizer. So improper rinsing limits the effectiveness of a sanitizer.

So , the answer is improper rinsing after that still a detergent residue remains limits the effectiveness of sanitizer.

7 0

3 years ago

The compound adrenaline contains 56.79% c, 6.56% h, 28.37% o, and 8.28% n by mass. what is the empirical formula for adrenaline?

Phoenix [80]

To determine the empirical formula of the compound given, we need to determine the ratio of each element in the compound. To do that we assume to have 100 grams sample of the compound with the given composition. Then, we calculate for the number of moles of each element. We do as follows:
mass moles
C 56.79 4.73
H 6.56 6.50
O 28.37 1.77
N 8.28 0.59

Dividing the number of moles of each element with the smallest value, we will have the empirical formula:

 moles ratio
C 4.73 / 0.59 8
H 6.50 / 0.59 11
O 1.77 / 0.59 3
N 0.59 / 0.59 1

The empirical formula would be C8H11O3N.

8 0

3 years ago