Answer:
A. 1 = 3 - 2
Explanation:
What defines an expression?
expression - An expression is a sentence with a minimum of two numbers and at least one math operation. This math operation can be addition, subtraction, multiplication, and division.
So if we look at the letter options we can see that A is the best choice.
Answer:

Explanation:
We know we will need an equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 261.34 233.39
Ba(NO₃)₂ + Na₂SO₄ ⟶ BaSO₄ + 2NaNO₃
m/g: 75.00
1. Moles of Ba(NO₃)₂

2. Moles of BaSO₄
The molar ratio is (1 mol BaSO₄/1 mol Ba(NO₃)₂

3. Mass of BaSO₄

Answer: The charge on the plates are 88.4 picafarad
Explanation:The equation used in measuring charge in a plate is given as:
C=Q/V =E A/D
Where E= dielectric content
A= Area of plates
d= distance between plates
Using dielectric constant for Air=8.84×10-12F/m
A=100cm2=0.01m2
d=10mm=0.001m
C= 8.84×10-12×0.01/0.001
C= 88.4 picafarad
Answer:PH2=0.994atm, mass of zinc=0.606g
Explanation:
Equation for the reaction is written as;
Zn(s) + 2HCl(aq) - ZnCl2(aq) + H2(g)
V= 240ml = 0.240L
T= 30.8oC = 303.8K
Ptotal= 1.036atm
Pwater = 32mmHg at 30oC = 0.042atm
Therefore
PH2 = Ptotal - Pwater
= 1.036-0.042atm
=0.994atm
But PV= nRT
n = PV/RT
= 0.994x0.240/0.0821x303.8
= 0.24/24.94
=0.009324moles
For the grams of zinc
n=mass in grams/molar mass
Mass in grams = no of moles x molar mass
=0.009324x65 = 0.606g