Answer:
The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.
Explanation:
Pressure in the container is P and volume is V.
Temperature of the helium gas molecules =
Molecules helium gas = x
Moles of helium has = 
PV = nRT (Ideal gas equation)
...[1]
After removal of helium gas only a fourth of the gas molecules remains and pressure in the container and volume should remain same.
Molecules of helium left after removal = 
Moles of helium has left after removal = 
...[2]
The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.
The combustion reaction is as expressed,
CxHy + O2 --> CO2 + H2O
The mass fraction of carbon in CO2 is 3/11. Hence,
mass of C in CO2 = (3.14 g)(3/11) = 0.86 g C.
Given that we have 1 g of the hydrocarbon, the mass of H is equal to 0.14 g.
moles of C = 0.86 g C / 12 g = 0.0713
moles of H = 0.14 g H / 1 g = 0.14
The empirical formula for the hydrocarbon is therefore, CH₂.
Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
<h3>
Answer:</h3>
The total concentration of ions in a 0.75 M solution of HCl is 1.5 M
That is; 0.75 M H⁺ and 0.75 M Cl⁻
<h3>
Explanation:</h3>
- Concentration or molarity is the number of moles of a compound or an ion contained in one liter of solution. It is measured in moles per liter (M).
- The concentration of ions making a compound is determined by the ratio of moles of the compound and the constituents ions.
- For instance, HCl dissociates to give H⁺ and Cl⁻
HCl(aq) → H⁺(aq) + Cl⁻(aq)
- Therefore, since the mole ratio between HCl and the constituent ions H⁺ and Cl⁻ is 1:1, then 0.75 M of HCl dissociates to give 0.75 M H⁺ and 0.75 m Cl⁻
- Hence the total concentration of ions in a 0.75 M solution of HCl is 1.5 M (0.75 M H⁺ and 0.75 M Cl⁻)
