An alpha particle is a helium nucleus without the electrons - 2 neutrons and 2 protons.
So, all you would have to do is 2 x 55, which equals 110.
Answer: It should a accepter
Explanation: because water is often used as solvent for solutes...there are exceptions
Answer:- 448 mL of hydrogen gas are formed.
Solution:- It asks to calculate the volume of hydrogen gas formed in milliliters at STP when 0.020 moles of magnesium reacts with excess HCl acid. The balanced equation is:
![Mg+2HCl\rightarrow MgCl_2+H_2(g)](https://tex.z-dn.net/?f=Mg%2B2HCl%5Crightarrow%20MgCl_2%2BH_2%28g%29)
There is 1:1 mol ratio between Mg and hydrogen gas. So, the moles of hydrogen gas is also equals to the moles of Mg reacted.
moles of Hydrogen gas formed = 0.020 mol
At STP, volume of 1 mol of the gas is 22.4 L. We need to calculate the volume of 0.02 moles of hydrogen gas.
![0.02mol(\frac{22.4L}{1mol})](https://tex.z-dn.net/?f=0.02mol%28%5Cfrac%7B22.4L%7D%7B1mol%7D%29)
= 0.448 L
They want answer in mL. So, let's convert L to mL using the conversion formula, 1L = 1000mL
![0.448L(\frac{1000mL}{1L})](https://tex.z-dn.net/?f=0.448L%28%5Cfrac%7B1000mL%7D%7B1L%7D%29)
= 448 mL
So, 0.020 moles of magnesium would produce 448 mL of hydrogen gas at STP on reacting with excess of HCl acid.
Answer:
![\Delta _RH=4x10^{-3}\frac{kJ}{mol}](https://tex.z-dn.net/?f=%5CDelta%20_RH%3D4x10%5E%7B-3%7D%5Cfrac%7BkJ%7D%7Bmol%7D)
Explanation:
Hello,
In this case, the molar enthalpy of reaction is obtained by dividing the involved energy by the reacting moles:
![\Delta _RH=\frac{12J}{3mol} =4\frac{J}{mol}](https://tex.z-dn.net/?f=%5CDelta%20_RH%3D%5Cfrac%7B12J%7D%7B3mol%7D%20%3D4%5Cfrac%7BJ%7D%7Bmol%7D)
Thus, it is important to notice that the compound "uses" the energy, it means that it absorbs the energy, for that reason the sign is positive. Moreover, computing the result in kJ/mol we finally obtain:
![\Delta _RH=4\frac{J}{mol}*\frac{1kJ}{1000J} =4x10^{-3}\frac{kJ}{mol}](https://tex.z-dn.net/?f=%5CDelta%20_RH%3D4%5Cfrac%7BJ%7D%7Bmol%7D%2A%5Cfrac%7B1kJ%7D%7B1000J%7D%20%3D4x10%5E%7B-3%7D%5Cfrac%7BkJ%7D%7Bmol%7D)
Best regards.