Answer:
two
Explanation:
The number of significant figures needed in the answer is 2.
This is because when finding the products of two numbers, the result is as accurate as the least number of significant figures of the numbers being multiplied.
Here the numbers being multiplied are;
1.31m
6.5m
1.31m has 3 significant figures
6.5m has 2 significant figures.
So, the product will have 2 significant figures
Because they are different they all show different traits
The answer for the following problem is described below.
<em><u> Therefore the standard enthalpy of combustion is -2800 kJ</u></em>
Explanation:
Given:
enthalpy of combustion of glucose(Δ
of 
) =-1275.0
enthalpy of combustion of oxygen(Δ of 
) = zero
enthalpy of combustion of carbon dioxide(Δ of 
) = -393.5
enthalpy of combustion of water(Δ of 
) = -285.8
To solve :
standard enthalpy of combustion
We know;
Δ = ∈Δ (products) - ∈Δ (reactants)
(s) +6 (g) → 6 (g)+ 6 (l)
Δ = [6 (-393.5) + 6(-285.8)] - [6 (0) + (-1275)]
Δ = [6 (-393.5) + 6(-285.8)] - [0 - 1275]
Δ = 6 (-393.5) + 6(-285.8) - 0 + 1275
Δ = -2361 - 1714 - 0 + 1275
Δ =-2800 kJ
<em><u> Therefore the standard enthalpy of combustion is -2800 kJ</u></em>
Answer:
a. polar solutes dissolve in polar solvents.
Explanation:
Polarity is a phenomenon that has to do with the positive and negative electric (ionic) charges of a molecule. A molecule with distinct positive and electric charge is said to be POLAR. However, water is said to be a universal solvent because it dissolves more substances than any other solvent can.
This solvent property of water is a function of its POLARITY. Polar solutes dissolve in polar solvents. Hence, only polar solutes can dissolve in water (a polar solvent). Hence, in this case, CH3OCH3 (ether) will dissolve in water because it is a POLAR molecule/solute.
