False, atoms can not be created that way
A covalent bond? Not sure how much detail you want, sorry
The dependant variable is what you measure during the experiment and what is affected in the experiment (this is for question 4) so the answer would be D
Answer:
0.88 g
Explanation:
Using ideal gas equation to calculate the moles of chlorine gas produced as:-

where,
P = pressure of the gas = 805 Torr
V = Volume of the gas = 235 mL = 0.235 L
T = Temperature of the gas = ![25^oC=[25+273]K=298K](https://tex.z-dn.net/?f=25%5EoC%3D%5B25%2B273%5DK%3D298K)
R = Gas constant = 
n = number of moles of chlorine gas = ?
Putting values in above equation, we get:

According to the reaction:-

1 mole of chlorine gas is produced when 1 mole of manganese dioxide undergoes reaction.
So,
0.01017 mole of chlorine gas is produced when 0.01017 mole of manganese dioxide undergoes reaction.
Moles of
= 0.01017 moles
Molar mass of
= 86.93685 g/mol
So,

Applying values, we get that:-

<u>0.88 g of
should be added to excess HCl (aq) to obtain 235 mL of
at 25 degrees C and 805 Torr.</u>