I have attached the answer. hopefully, i read the problems correctly. let me know if I did not.
both problems are an example of beta decays. when an atoms' atomic number is increased by one. this is symbolized with -1 e
Because more than one substance was released (following a color change signifying a chemical reaction), the sample was indeed, a compound.
Answer:
- There will be 1.23 moles of helium in the balloon at STP
Explanation:
1) <u>Initial conditions of the helium gas</u>:
- V = 20.0 liter
- p = 1.50 atm
- T = 25.0 °C = 25.0 + 273.15 K = 298.15 K
2) <u>Ideal gas equation</u>:
- pV = n RT
- p, V, and T are given above
- R is the Universal constant = 0.0821 atm-liter / ( K - mol)
- n is the unknown number of moles
3) <u>Solve for n</u>:
- n = 1.50 atm × 20.0 liter / (0.0821 atm-liter /k -mol ×298.15K)
4) <u>At STP:</u>
- STP stands for standard pressure and temperature.
- The amount (number of moles) of the gas will not change because the change of pressure and temperature, so the number of moles reamain the same: 1.23 mol.
The answer is Rubidium (Rb)
I think the correct answer from the choices listed above is the first option. She concluded that the reaction is an exothermic one because t<span>he reaction released heat. Exothermic is when heat goes out of the system. The opposite is referred to as an endothermic reaction.</span>
