Answer:
Melting of ice is a physical change and during this change latent heat of fusion, that is, heat required to convert 1 g of a solid substance into liquid state will keep the temperature constant unless and until all the solid changes into liquid. On the other hand, a change in which a new product is formed due to change in chemical composition of the reacting species is known as a chemical change. During a chemical change, there will occur change in temperature. So, when a substance is set on fire then there will occur change in temperature of the substance. Hence, it means it is a chemical change.
Explanation:
Let me know if you need more clarification!!!
Quartz has the formula SiO2
From the periodic table:
mass of oxygen = 16 grams
mass of silicon = 28.0855 grams
Mass of one mole of quarts = 28.0855 + 2(16) = 60.0855 grams
number of moles = mass / molar mass
number of moles = 1.6 / 60.0855 = 0.0266 moles
Each mole of quartz contains Avogadro's number of atoms.
Therefore:
number of atoms in 1.6 g = 1.6 x 6.02 x 10^23 = 1.603 x 10^22 atoms
Answer:
![r=25M^{-1}s^{-1}[A]^2](https://tex.z-dn.net/?f=r%3D25M%5E%7B-1%7Ds%5E%7B-1%7D%5BA%5D%5E2)
Explanation:
Hello there!
In this case, according to the given information for this chemical reaction, it is possible for us to set up the following general rate law and the ratio of the initial and the final (doubled concentration) condition:
![r=k[A]^n\\\\\frac{r_1}{r_2} =\frac{k[A]_1^n}{k[A]_2^n}](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5En%5C%5C%5C%5C%5Cfrac%7Br_1%7D%7Br_2%7D%20%3D%5Cfrac%7Bk%5BA%5D_1%5En%7D%7Bk%5BA%5D_2%5En%7D)
Next, we plug in the given concentrations of A, 0.2M and 0.4 M, the rates, 1.0 M/s and 4.0 M/s and cancel out the rate constants as they are the same, in order to obtain the following:
Which means this reaction is second-order with respect to A. Finally, we calculate the rate constant by using n, [A] and r, to obtain:
![k=\frac{r}{[A]^n} =\frac{1.0M/s}{(0.2M)^2}\\\\k=25M^{-1}s^{-1}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7Br%7D%7B%5BA%5D%5En%7D%20%3D%5Cfrac%7B1.0M%2Fs%7D%7B%280.2M%29%5E2%7D%5C%5C%5C%5Ck%3D25M%5E%7B-1%7Ds%5E%7B-1%7D)
Thus, the rate law turns out to be:
Regards!
You need to use the % information to determine the empirical formula of the compound first.
The empirical formula is the simplest ratio of atoms in the molecule.
Then use the rest of the data to determine moles of gas, and use this to determine molar mass of gas...
Empirical formula calculations:
Assume you have 100 g, calculate the moles of each atom in the 100 g
moles = mass / molar mass
molar mass C = 12.01 g/mol
molar mass H = 1.008 g/mol
molar mass O = 16.00 g/mol
C = 64.9 % = 64.6 g
H = 13.5 % = 13.5 g
O = 21.6 % = 21.6 g
moles C = 64.6 g / 12.01 g/mol = 5.38 mol
moles H = 13.5 g / 1.008 g/mol = 13.39 mol
moles O = 21.6 g / 16.00 g/mol = 1.35 mol
So ratio of C : H : O
is 5.38 mol : 13.39 mol : 1.35 mol
Divide each number in the ratio by the lowest number to get the simplest whole number ratio
(5.38 / 1.35) : (13.39 / 1.35) : (1.35 / 1.35)
4 : 10 : 1
empirical formula is
C4H10O
Finding moles and molar mass calcs
Now, you know that at 120 deg C and 750 mmHg that 1.00L compound weighs 2.30 g.
We can use this information to determine the molar mass of the gas after first working out how many moles the are in the 1.00 L
PV = nRT
P = pressure = 750 mmHg
V = volume = 1.00 L
n = moles (unknown)
T = temp in Kelvin (120 deg C = (273.15 + 120) Kelvin)
- T = 393.15 Kelvin
R = gas constant, which is 62.363 mmHg L K^-1 mol^-1 (when your P is in mmHg and volume is in L)
n = PV / RT
n = (750 mmHg x 1.00 L) / (62.363mmHg L K^-1 mol^-1 x 393.15 K)
n = 0.03059 moles of gas
We know moles = 0.03509 and mass = 2.30 g
So we can work out molar mass of the gas
moles = mass / molar mass
Therefore molar mass = mass / moles
molar mass = 2.30 g / 0.03059 mol
= 75.19 g/mol
Determine molecular formula
So empirical formula is C4H10O
molar mass = 75.19 g/mol
To find the molecular formula you divide the molar mass by the formula weight of the empirical formula...
This tells you how many times the empirical formula fits into the molecular formula. Tou then multiply every atom in the empirical formula by this number
formula weight C4H10O = 74.12 g/mol
Divide molar mass by formula weight empirical
75.15 g/mol / 74.12 g/mol
= 1
(It doesn't matter that the number don't quite match, they rarely do in this type of calc (although I could have made a slight error somewhere) but the numbers are very close, so we can say 1.)
The empirical formula only fits into the molar mass once,
molecular formula thus = empirical formula
<span>
C4H10O
Therefore, the </span>molecular formula of the compound is <span>C4H10O.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!</span>
Explanation:
(a) Formula that shows relation between 
and 
is as follows.
Here, 
= 1
Putting the given values into the above formula as follows.
= 
= 
= 0.01316
(b) As the given reaction equation is as follows.
As there is only one gas so
,
![p[CO_{2}] = K_{p}](https://tex.z-dn.net/?f=p%5BCO_%7B2%7D%5D%20%3D%20K_%7Bp%7D)
= 1.20
Therefore, pressure of 
in the container is 1.20.
(c) Now, expression for for the given reaction equation is as follows.
![K_{c} = \frac{[CaO][CO_{2}]}{[CaCO_{3}]}](https://tex.z-dn.net/?f=K_%7Bc%7D%20%3D%20%5Cfrac%7B%5BCaO%5D%5BCO_%7B2%7D%5D%7D%7B%5BCaCO_%7B3%7D%5D%7D)
= 
= \frac{x^{2}}{(a - x)}[/tex]
where, a = initial conc. of 
= 
= 0.023 M
0.0131 = 
x = 0.017
Therefore, calculate the percentage of calcium carbonate remained as follows.
% of remained = 
= 75.46%
Thus, the percentage of calcium carbonate remained is 75.46%.
