Answer: 21 lawns per week
Explanation:
The average weekly rate refers to how many lawns were mowed per week given that 233 were done in 11 weeks.
Rate will be given by;
= Lawns mowed / Weeks taken
= 233 / 11
= 21 lawns per week
Answer:
substance
Explanation:
A pure substance is a form of matter that has a constant composition (meaning it's the same everywhere) and properties that are constant throughout the sample (meaning there is only one set of properties such as melting point, color, boiling point, etc
Answer:
∴ Fractional distillation is the technique used to separate the fraction
Explanation:
A: Refinery gas
B: Gasoline fraction
C: Naphtha
D: Kerosene
E: Diesel Oil
F: Fuel oil fraction
G: Lubricating fraction
H: Bitumen
Answer:

Explanation:
Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.
With Hess's Law in mind, let's see how A can be converted to 2C +E.
(Δ
) -----(1)
Since we have 2B, multiply the whole of II. by 2:
(2Δ
) -----(2)
This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is
.
Reversing III. gives us a negative enthalpy change as such:
(-Δ
) -----(3)
This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of
, which is also the equation of interest.
Adding all three together:
(
)
Thus, the first option is the correct answer.
Supplementary:
To learn more about Hess's Law, do check out: brainly.com/question/26491956
166.4 g Ag grams of silver can be produced from 49.1 g of copper.
<h3>What is a mole?</h3>
A mole is a very important unit of measurement that chemists use. A mole of something means you have 602,214,076,000,000,000,000,000 of that thing, like how having a dozen eggs means you have twelve eggs.
→ 
63.55 g Cu —> 2 x 107.688 g Ag
63.55 g Cu gives 215.376 g of Ag
So, 49.1 g Cu —> 
= 166.4 g Ag
Hence, 166.4 g Ag grams of silver can be produced from 49.1 g of copper.
Learn more about moles here:
brainly.com/question/26416088
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