Answer:
I think it's B
Explanation:
I might be wrong, but please tell me.
Number of moles is defined as the ratio of given mass in g to the molar mass.
The mathematical formula is:
Number of moles =
(1)
Number of zinc atoms is equal to
, by Avogadro number, number of moles can be calculated.
As, 1 mol=
atoms, hence,

= 0.2822 mol
Now, from formula (1), calculate mass in g (molar mass of zinc = 65.4 g/mol)
0.2822 mol =
mass in g = 
= 18.45588 g
Thus, by rounding off the above number, it will come near about 19 g approximately.
Hence, option (C) is the correct answer.
Answer:
B) 12
Explanation:
Given parameters:
Initial volume = 3L
Initial pressure = 4atm
Final pressure = 6atm
Unknown:
Final volume = ?
Solution:
To solve this problem, we apply Boyle's law which states that "the volume of a fixed mass of a gas varies inversely as the pressure changes if the temperature is constant".
P₁V₁ = P₂V₂
P and V are pressure and temperature values
1 and 2 are initial and final states.
PV product = 3 x 4 = 12
Answer:
100 mL
Explanation:
The reaction that takes place is:
- CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
First we <u>convert 500 mg of CaCO₃ into mmoles</u>, using its <em>molar mass</em>:
- 500 mg ÷ 100 mg/mmol = 5 mmol CaCO₃
Then we <u>convert 5 mmoles of CaCO₃ into HCl mmoles</u>, using the <em>stoichiometric coefficients of the balanced reaction</em>:
- 5 mmol CaCO₃ *
= 10 mmol HCl
Finally we <u>calculate the volume of a 0.10 M HCl solution (such as stomach acid) that would contain 10 mmoles</u>:
- 10 mmol / 0.10 M = 100 mL
C) Steam has the most energy.
Steam has more energy than Ice and Water because the particles in ice are close together, the particles in water flow more loosely than in a solid like ice and in steam they are very active.
I hope that helps u understand :)