Answer:
The answer is 2.107 × 10²⁴ He atoms
Explanation:
To find the number of atoms given the number moles we use the formula
<h3>N = n × L</h3>
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
N = 3.5 × 6.02 × 10²³
We have the final answer as
<h3>2.107 × 10²⁴ He atoms</h3>
Hope this helps you
Answer:
Explanation:
3.
Knowns: 100mL of solution; concentration of 0.7M
Unknown: number of moles
Equation: number of moles = volume * concentration
Plug and Chug: number of moles = 100/1000 * 0.7 = 0.07 mole
Final Answer: 0.07mole
2.
Knowns: 5.50L of solution; concentration of 0.400M
Unknown: number of moles
Equation: number of moles = volume * concentration
Plug and Chug: number of moles = 5.5 * 0.4 = 2.20 mole
Final Answer: 2.20 mole
Answer:
3.14 grams of ammonium thiocyanate must be used to react completely with 6.5 g barium hydroxide octahydrate.
Explanation:

The balance chemical equation is :

Mass of barium hydroxide octahydrate = 6.5 g
Moles of barium hydroxide octahydrate = 
According to reaction, 2 moles of ammonium thiocyanate reacts with1 mole of barium hydroxide octahydrate. The 0.020635 moles of barium hydroxide octahydrate will react with:

Mass of 0.04127 moles of ammonium thiocyanate;

3.14 grams of ammonium thiocyanate must be used to react completely with 6.5 g barium hydroxide octahydrate
Sissy imposter among us haha