1) Number of neutrons of Fluorine -19
The number 19 is the mass number of the atom.
The atomic number of fluorine is 9, which means it has 9 protons (which is constant for any atom of fluor
The number of protons is calculated as the mass number - atomic number = 19 - 9 = 10.
So, look for which of the other atoms have 10 neutrons
2)
element mass number atomic number number of neutrons
Neon-20 20 10 20 - 10 = 10
Oxygen-19 19 8 19 - 8 = 11
Sodium-22 22 11 22 - 11 = 11
Nitrogen-16 16 7 16 - 7 = 9
So, the atom that has the same number of nuetrons as Fluorine-19 is Neon-20
Answer:
c = 4
Explanation:
In general, for the reaction
a A + b B ⇒ c C + d D
the rate is given by:
rate = - 1/a ΔA/Δt = - 1/b ΔB/Δt = + 1/c ΔC/Δt = + 1/d ΔD/Δt
this is done so as to express the rate in a standarized way which is the same to all the reactants and products irrespective of their stoichiometric coefficients.
For this question in particular we know the coefficient of A and need to determine the coefficient c.
- 1/2 ΔA/Δt = + 1/c ΔC/Δt
- 1/2 (-0.0080 ) = + 1/c ( 0.0160 mol L⁻¹s⁻¹ )
0.0040 mol L⁻¹s⁻¹ c = 0.0160 mol L⁻¹s⁻¹
∴ c = 0.0160 / 0.0040 = 4
Answer:
Hydrogen fuel cells do not produce any CO2 emissions during operation, even if their production is not necessarily carbon-free. This gives them an advantage over combustion engine vehicles, which can emit small amounts of poisonous carbon monoxide and require well-ventilated rooms for indoor use.
Answer:
1. Qsol = -5.87 kJ
2. ΔHrn = 18.4 kJ/mol
Explanation:
According to the law of conservation of energy, the sum of the heat absorbed by the reaction and the heat released by the solution is zero.
Qrn + Qsol = 0
Qrn = -Qsol
We can calculate the heat released by the solution using the following expression.
Qsol = c . m . ΔT
where,
c: specific heat capacity of the solution
m: mass of the solution
ΔT: change in the temperature
Qsol = (4.184 J/g.°C) . (243g + 32.3g) . (17.90°C-23.00°C) = -5.87 × 10³ J = -5.87 kJ
The heat absorbed by the reaction is:
Qrn = -Qsol = 5.87 kJ
In the balanced equation, we have 1 mole of KNO₃. Given we are in a constant-pressure calorimeter, the enthalpy of reaction (per mole of KNO₃) is:
Answer:
A
Explanation:
I think it's pressure. Using the process of elimination, sediment is the matter that's on the bottom of a liquid or solution, deposition is the process of deposing, eruption is the process of erupting, and pressure's formula is force/area, so pressure is the answer.