Answer:
Explanation:
Given the details, we can say that
Pure methanol is a volatile solvent as the vapour pressure has a high value. This means that methanol - methanol intermolecular forces are weak in comparisson to water - water forces. When having about 30% of water in a methanol mixture, the mixture Pv decreased, showing that it is not a volatile mixture, so then there are strong intermolecular interactions between methanol - water, part of it due to the hydrogen bonds.
Explanation:
The given data is as follows.
Mass of antimony = 19.75 g
Molar mass of Sb = 121.76 g/mol
Therefore, calculate number of moles of Sb as follows.
Moles of Sb = 
= 
= 0.162 mol
Mass of oxygen given is 6.5 g and molar mass of oxygen is 16 g/mol. Hence, moles of oxygen will be calculated as follows.
Moles of oxygen =
= 
= 0.406 mol
Hence, ratio of moles of Sb and O will be as follows
Sb : O
1 : 2.5
We multiply both the ratio by 2 in order to get a whole number. Therefore, the ratio will be 2 : 5.
Thus, we can conclude that the empirical formula of the given oxide is 
.
Bed rock is a layer underneath minerals
These are the answer options of this question and the comments about their validity:
<span>A) It dictates that the number of molecules on each side of a chemical equation must be the same.
False: the number of molecules can change. Take this simple reaction for example:
2H2(g) + O2 -> 2H2O
You start with 3 molecules, 2 molecules of H2 and 1 molecule of O2, and end with 2 molecules of water. Then the number of molecules of each side is different.
B) It dictates that the number of atoms of each element must be the same on both sides of a chemical equation.
TRUE: in a chemical reaction the atoms remain being the same at start and at the end of the process. Given that each atom has a characteristic mass, their conservation implies the law of conservation mass.
C) It states that the mass of the reactants must remain constant in order for a chemical reaction to proceed.
FALSE. The mass of the reactants changes during a chemical reaction, while they transform into the products.
D) It does not apply to chemical reactions.
FALSE: It is an important law used in the calculus related with chemical reactions.
</span>
Answer:
B. Changes in the Moon's visibility.
Explanation:
The moon's shifting of position makes it "appear" as being smaller or bigger. This is simply because the moon is rotating and the sun's light shines on a certain area of the moon, and depending on where we are on the Earth is how the moon looks or appears to our perspective.
