Answer:
The percentage (by mass) of KBr in the original mixture was 33.1%.
Explanation:
The mixture of KCl and KBr has a mass of 3.595g, thus the sum of the moles of KCl (<em>x</em>) multiplied by it molar mass (74.5g/mol) and the moles of KBr (<em>y</em>) multiplied by it molar mass (119g/mol) is the total mass of the mixture:
Also, after the conversion of KBr into KCl, the total mass of 3.129 g is only from KCl moles, hence
But the 0.042 moles came from the originals KCl and KBr moles, thus
Now it is possible to propose a system of equations:
Solving the system of equations,
0.010 moles of KBr multiplied it molar mass is
Therefore, the percentage (by mass) of KBr in the original mixture was:
%
Answer:
The chemical formula does not show how the atoms are connected to one another.
Explanation:
With a chemical formula, you can see the types of elements that make up the compound, the number of atoms of each element in a molecule, and the chemical symbols of the elements in the compound.
They are all <u>non-metal elements</u>.
Those tails are called hydrophobic. You can note the etymology: hydro= water, phobi = fear, aversion, dislike.
Phospholipds' tail is a long non polar chain, made of Carbon and Hydorgens, that rejects water (a polar solvent) and is attracted to non-polar compounds (oil for example). That is why that tails can atract dirt.
The answer is A. <span>The substance changed shape.
There you go!</span>
