Answer:
Neon
Explanation:
Step 1: Given and required data
- Density of the gas (ρ): 1.57 g/L
- Ideal gas constant (R): 0.08206 atm.L/mol.K
Step 2: Convert T to Kelvin
We will use the following expression.
K = °C + 273.15 = 40.0 + 273.15 = 313.2 K
Step 3: Calculate the molar mass of the gas (M)
For an ideal gas, we will use the following expression.
ρ = P × M/R × T
M = ρ × R × T/P
M = 1.57 g/L × 0.08206 atm.L/mol.K × 313.2 K/2.00 atm
M = 20.17 g/mol
The gas with a molar mass of 20.17 g/mol is Neon.
Answer:
Photon of light
Explanation:
According to Bohr's model of the atom, electrons in atoms are found in specific energy levels. These energy levels are called stationary states, an electrons does not radiate energy when it occupies any of these stationary states.
However, an electron may absorb energy and move from one energy level or stationary state to another. The energy difference between the two energy levels must correspond to the energy of the photon of light absorbed in order to make the transition possible.
Since electrons are generally unstable in excited states, the electron quickly jumps back to ground states and emits the excess energy absorbed. The frequency or wavelength of the emitted photon can now be measured and used to characterize the transition. This is the principle behind many spectrometric and spectrophotometric methods.
<h2><em>1. A</em></h2><h2><em>3. B</em></h2><h2><em>4. C</em></h2><h2><em>7. E</em></h2><h2><em>5. F</em></h2>
The concentration of mixed solution = 0.5 M
<h3>
Further explanation
</h3>
Given
0.5 M HCl
0.5 M Ca(OH)₂
Required
The concentration
Solution
Molarity from 2 solutions :
Vm Mm = V₁. M₁ + V₂. M₂
m = mixed solution
V = volume
M = molarity
V = mixed volume
1 = solution 1
2 = solution 2
Vm = V₁+V₂
Equal volumes⇒V₁=V₂, and Vm = 2V, then equation becomes :
2V.Mm = V(M₁+M₂)
2V.Mm = V(0.5+0.5)
Mm=0.5 M
