Answer:
54g
Explanation:
Given parameters:
Number of moles of H₂O = 3 moles
Unknown:
mass of water = ?
Solution:
To solve this problem, we use the expression below:
mass = number of moles x molar mass
Molar mass of H₂O = 2(1) + 16 = 18g/mol
Mass of water = 3 x 18 = 54g
Answer:
14 mL
Explanation:
To prepare a solution by a concentrated solution, we must use the equation:
C1xV1 = C2xV2, where <em>C</em> is the concentration, <em>V</em> is the volume, 1 is the initial solution and 2 the final solution.
The final solution must have 2 mL and a concentration of 350 pg/mL, and the initial solution has a concentration of 50 pg/mL.
Then:
50xV1 = 350x2
50xV1 = 700
V1 = 700/50
V1 = 14 mL
Answer:
19.07 g mol^-1
Explanation:
The computation of the molecular mass of the unknown gas is shown below:
As we know that

where,
Diffusion rate of unknown gas = 155 mL/s
CO_2 diffusion rate = 102 mL/s
CO_2 molar mass = 44 g mol^-1
Unknown gas molercualr mass = M_unknown
Now placing these values to the above formula

After solving this, the molecular mass of the unknown gas is
= 19.07 g mol^-1
<u>Answer:</u> The correct answer is 0.745 km
<u>Explanation:</u>
We are given:
A numerical value of 815 yards
To convert this into kilometers, we use the conversion factor:
1 km = 1093.6 yards
Converting the given value into kilometers, we get:

Hence, the correct answer is 0.745 km
Answer:
Neutrons = ( Atomic mass – Atomic number ) ( A–Z )
Protons and Electrons are equal to the atomic number
For example Neon,
Mass number (A) = 20
Atomic Number (Z) = 10
Number of Protons = 10
Number of Electrons = 10
Number of Neutrons = ( A–Z ) = 10
Electronic distribution :
K= 2
L= 8