It is a <u><em>chemical compound</em></u> formed with a metal (mainly positive cations) with oxygen.
It is formed through the air as they react in the air together.
They are also BASES - ALKALINE (so neutralise acids)
17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
Tim and Dan should expect to measure simple evaporation to happen at the end of their experiment.
Answer:
D) HCOOCH2CH3
Explanation:
An isomer of a compound is defined as a chemical substances with the same formula (That is, same atoms) but in different structures.
For propanoic acid, there are <em>3 atoms of C, 6 atoms of H and 2 atoms of oxygen.</em>
A) CH2CHCOOH
. Here you have 3 atoms of C but 4 atoms of H. That means this compound is not an isomer.
B) CH3CH2CH2COOH
. Here, there are 4 atoms of C. Thus, is not an isomer.
C) CH3CH(OH)CH2OH. This structure has 3 atoms of C, but 8 atoms of H. Thus, is not an isomer.
D) HCOOCH2CH3. Here, there are 3 atoms of C, 6 atoms of H and 2 atoms of O. Thus, this structure <em>is an isomer of propanoic acid.</em>
Technically the answer would be a