Answer: The mass is 348.8g
Explanation:
We begin by using Avogadro's number to convert the number of molecules of Sodium Hydroxide to moles.
6.02 x 10∧23 molecules of NaOH -------> 1 mole of NaOH
∴ 5.25 x 10∧24 molecules of NaOH -------> 1/ 6.02 x 10∧23 x 5.25 x 10∧24 =
8.72moles.
Having found the number of moles, we then move from moles to gram by using the molar mass of NaOH (i.e the mass of 1 mole of NaOH).
1 mole of NaOH is equivalent to 40g (Molar Mass)
8.72 moles of NaOH would be equivalent to; 40/ 1 x 8.72 = 348.8g
The mass in 5.25 x 10∧24molecules of NaOH is 348.8g
Answer:
A. it is the lowest at low temperatures
Explanation:
At low temperature the kinetic energy of a molecule is low. The kinetic energy is directly proportional to the temperature of the molecule. The kinetic energy of a molecule increases with the increase in the temperature that energize the molecules of a substance and makes them to move faster than before.
As the kinetic energy is proportional to temperature so it does not increase with decrease in the temperature (low temperature). The kinetic energy varies with the change in the temperature and it is not same at all temperature. The kinetic energy is highest at high temperature. Thus, option A is correct.
It depends, for example, it is quite important to know the Kelvin scale (i.e 0 degrees Celsius is 273 K and -273 degrees Celsius is 0 K ) when dealing gases. But I don't know other situations where you would need to know other temperature scales.
Hope this helps and also if you are using Fahrenheit 1 Fahrenheit is -17.22 degrees Celsius
Moles KClO₃ = 0.239
<h3>Further explanation</h3>
Given
Reaction
2KClO₃(s) ⇒2KCl(s) + 3O₂(g)
P water = 23.8 mmHg
P tot = 758 mmHg
V = 9.07 L
T = 25 + 273 = 298 K
Required
moles of KClO₃
Solution
P tot = P O₂ + P water
P O₂ = P tot - P water
P O₂ = 758 - 23.8
P O₂ = 734.2 mmHg = 0.966 atm
moles O₂ :
n = PV/RT
n = 0.966 x 9.07 / 0.082 x 298
n = 0.358
From equation, mol ratio KClO₃ : O₂ = 2 : 3, so mol KClO₃ :
= 2/3 x mol O₂
= 2/3 x 0.358
= 0.239
