Answer : The volume of liquid is 420 mL.
Explanation :
Density : The mass per unit volume of a substance is known as density.
Formula used:

As we are given:
Density of mercury = 13.5 g/mL
Mass = 12.5 pounds
First we have to convert mass of sample from pound to gram.
Conversion used:
As, 1 pound = 453.6 g
So, 12.5 pounds = 453.6 × 12.5 g = 5670 g
Now we have to calculate the volume of liquid.

Now putting all the given values in this formula, we get:

Volume = 420 mL
Therefore, the volume of liquid is 420 mL.
Answer:
The answer to your question is 160 g of Fe₂O₃
Explanation:
Data
mass of Fe = 112 g
mass of CO = in excess
mass of Fe₂O₃ = ?
Balanced chemical reaction
Fe₂O₃ + 3CO ⇒ 2Fe + 3CO₂
Process
1.- Calculate the molar mass of Fe₂O₃ and Fe
Molar mass Fe₂O₃ = (56 x 2) + (16 x 3) = 112 + 48 = 160 g
atomic mass of Fe = 56
2.- Use proportions to calculate the mass of Fe₂O₃ needed
160 g of Fe₂O₃ ------------------- 2(56) g of Fe
x g of Fe₂O₃ ------------------ 112 g of Fe
x = (112 x 160) / 2(56)
x = 17920/112
x = 160 g of Fe₂O₃
True, biodiversity creates different species animals depend on each other for food and other reasons so the answer is true.
Answer:
1.58x10⁻⁵
2.51x10⁻⁸
0.0126
63.10
Explanation:
Phenolphthalein acts like a weak acid, so in aqueous solution, it has an acid form HIn, and the conjugate base In-, and the pH of it can be calculated by the Handerson-Halsebach equation:
pH = pKa + log[In-]/[HIn]
pKa = -logKa, and Ka is the equilibrium constant of the dissociation of the acid. [X] is the concentrantion of X. Thus,
i) pH = 4.9
4.9 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = - 4.8
[In-]/[HIn] = 
[In-]/[HIn] = 1.58x10⁻⁵
ii) pH = 2.1
2.1 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = -7.6
[In-]/[HIn] = 
[In-]/[HIn] = 2.51x10⁻⁸
iii) pH = 7.8
7.8 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = -1.9
[In-]/[HIn] = 
[In-]/[HIn] = 0.0126
iv) pH = 11.5
11.5 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = 1.8
[In-]/[HIn] = 
[In-]/[HIn] = 63.10