Let us assume that there is a 100g sample of Opal. The masses of each element will be:
29.2g Si
33.3g O
37.5g H2O
Now we divide each constituent's mass by its Mr to get the moles present
Si: (29.2 / 28) = 1.04
O: (33.3 / 16) = 2.08
H2O: (37.5 / 18) = 2.08
Now we divide by the smallest number and obtain:
Si: 1
O: 2
H2O: 2
Thus, the empirical formula of Opal is:
SiO2 . 2H2O
Answer:
15.98 L
Explanation:
First, you need to find T1, T2, V1 and V2.
T1 = 25 C = 298.15 K (25C + 273.15K)
T2 = 100 C = 373.15 K (100C + 273.15K)
V1 = 20. L
V2 = ? (we are trying to find)
Next, rearrange to fit the formula
V2 = V1 x T1 / T2
Next, fill in with our numbers
V2 = 20. L x 298.15 K / 373.15 K
Do the math and you should get...
15.98 L
- If you need more help or futher explanation please let me know. I would be glad to help!
Answer:
∆H or Enthalpy of the reaction
Explanation:
If ∆H is +ve
- Reaction is exothermic
- Example:-Combustion, mixing sodium/potassium in water
If ∆H is -ve
- Reaction is endothermic
- Ex:-Melting of ice
Answer:
A scientific method is a method of research in which a problem is identified, relevant data are gathered, a hypothesis is formulated from these data, and the hypothesis is empirically tested.
Explanation:
Hope this helps! Mark Brainliest plz
Answer:
(a) C5H8O2
(b) C2H2Cl2
(c) CH2
(d) CH
Explanation:
We need to find the proportion of the atoms in whole numbers. Given the percentages we can calculate the number of moles and find their proportions.
Assume 100 g and given the atomic weights the moles are calculated.
(a) C = 59.9/ 12.01 = 4.98 ≈ 5.00
H = 8.06/1.007 = 8.00
O = 32/15.999 = 2.00
C5H8O2
(b) C= 24.8/12.01 = 2.06≈ 2.00
H = 2.0/1.007 = 1.99 ≈ 2.00
Cl = 73.1/ 35.453 = 2.06 ≈ 2.00
C2H2Cl2
(c) C = 86/12.01 = 7.16
H= 14/1.007 = 13.90
7.16:13.90 ≈ 1:2
CH2
(d) C = 92.30/12.01 = 7.68
H = 7.7 / 1.007 = 7.65
7.68:7.65 ≈ 1:1
CH
