Answer:
Mass of ammonia = 34 g
Explanation:
Given data:
Number of molecules of ammonia = 1.204 × 10²⁴
Mass of ammonia = ?
Solution:
First of all we will calculate the number of moles.
one mole of ammonia = 6.022 × 10²³ molecules
n = 1 mole/6.022 × 10²³ molecules × 1.204 × 10²⁴ molecules
Number of moles = 2 mol
Mass of ammonia:
Number of moles = Mass / molar mass
Mass of ammonia = number of moles × molar mass
Mass of ammonia = 2 mol × 17 g/mol
Mass of ammonia = 34 g
Answer: A volume of 37.5 mL of 0.300 M NaF would be required to make a 0.0450 M solution of NaF when diluted to 250.0 mL with water.
Explanation:
Given: = 0.300 M, = ?
= 0.0450 M, = 250.0 mL
Formula used is as follows.
Substitute the values into above formula as follows.
Thus, we can conclude that a volume of 37.5 mL of 0.300 M NaF would be required to make a 0.0450 M solution of NaF when diluted to 250.0 mL with water.
The second one- new substances that are present at the end of a reaction
Answer:
B. False
Explanation:
All the atoms of an element are not entirely the same no matter where they are found.
The phenomenon of isotopy brings a different perspective to the identity of an element.
- Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- Isotopes of an element have the same electrons but differ in their masses.
- They also differ in their chemical properties.
I think the C but im not sure about it