Explanation:
Combustion produces energy. Where does all this energy come from? Energy is stored in the chemical bonds that hold the carbon and hydrogen atoms together. When the atoms are rearranged, the bonds are broken, releasing energy.
Answer:- 0.800 moles of the gas were collected.
Solution:- Volume, temperature and pressure is given for the gas and asks to calculate the moles of the gas.
It is an ideal gas law based problem. Ideal gas law equation is used to solve this. The equation is:
PV=nRT
Since it asks to calculate the moles that is n, so let's rearrange this for n:
V = 19.4 L
T = 17 + 273 = 290 K
P = 746 mmHg
we need to convert the pressure from mmHg to atm and for this we divide by 760 since, 1 atm = 760 mmHg
P = 0.982 atm
R =
Let's plug in the values in the equation to get the moles.
n = 0.800 moles
So, 0.800 moles of the gas were collected.
Answer:
a. 0.20 M HF and 0.10 M NaOH.
c. 0.10 M HF and 0.10 M NaF
d. 0.10 M HCl and 0.20 M NaF.
Explanation:
A buffer solution consists of a weak acid and its conjugate base, or of a weak base and its conjugate acid.
In this case, <u>HF is the weak acid and F⁻ is its conjugate base</u>.
Let's go case-by-case:
a. 0.20 M HF and 0.10 M NaOH.
- Some -but not all- HF will react and produce F⁻, leaving a buffer solution.
b. 0.10 M HF and 0.10 M NaOH.
- All HF will react, not a buffer solution.
c. 0.10 M HF and 0.10 M NaF.
- There's no reaction, and both HF and F⁻ are directly added, it is a buffer solution.
d. 0.10 M HCl and 0.20 M NaF.
- Some F⁻ will react and produce HF, leaving a buffer solution.
The correct answers are A), C) and D).
Answer:
Convection currents are caused by the movement of the magma in the mantle.
Explanation: