Which of the following are supported by many observations
A- hypothesis
B- laws
C- theories
Laws and Theories
Answer:
27.99 dm³
Explanation:
Applying
PV = nRT................ Equation 1
Where P = Pressure, V = Volume, n = number of mole, R = molar gas constant, T = Temperature.
From the question, we were aksed to find V.
Therefore we make V the subject of the equation
V = nRT/P................ Equation 2
Given: n = 1.31 moles, T = 37°C = 310K, P = 904 mmHg = (904×0.001316) = 1.1897 atm
Constant: R = 0.082 atm.dm³/K.mol
Substitute these values into equation 2
V = (1.31×310×0.082)/(1.1897)
V = 27.99 dm³
Answer:
37.5 g NaCl
Explanation:
Step 1: Given data
- Concentration of NaCl: 15.0% m/m
- Mass of the solution: 250.0 g
Step 2: Calculate how many grams of NaCl are in 250.0 g of solution
The concentration of NaCl is 15.0% by mass, that is, there are 15.0 g of NaCl every 100 g of solution.
250.0 g Solution × 15.0 g NaCl/100 g Solution = 37.5 g NaCl
These are three questions and three complete answers
Answer:
a) Cr²⁺: [Ar] 4s² 3d²
b) Cu²⁺: [Ar] 4s² 3d⁷
c) Co³⁺: [Ar] 4s² 3d⁴
Explanation:
<u>a) Cr²⁺</u>
- Number of elecrons of the neutral atom: 24
- Number of electrons of the ion: 24 - charge = 24 - 2 = 22.
Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....
Hence, for 22 electrons you get:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d²
- Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:
[Ar] 4s² 3d²
<u>b) Cu²⁺</u>
- Number of elecrons of the neutral atom: 29
- Number of electrons of the ion: 29 - charge = 29 - 2 = 27.
Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....
Hence, for 27 electrons you get:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷
- Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:
[Ar] 4s² 3d⁷
<u>c) Co³⁺</u>
- Number of elecrons of the neutral atom: 27
- Number of electrons of the ion: 27 - charge = 27 - 3 = 24.
Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....
Hence, for 24 electrons you get:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴
- Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:
[Ar] 4s² 3d⁴
