The
combustion of heptane (C7H16) in oxygen spontaneously occurs. The products of
the reaction are carbon dioxide and water vapor. The balanced chemical equation
is 7H16 + 11O2 → 7CO2 + 8H2O H
= –2877.5 kJ.
Answer:

Explanation:
The first step is the <u>calculation of the moles</u> of
and
, so:


Now, in 1 mol of CO2 we have 1 mol of C and in 1 mol of
we have 1 mol of H. Additionally, if we want to calculate the moles of oxygen we need to <u>calculate the grams of C and O</u> and then do the <u>substraction</u> form the initial amount, so:


Now we can <u>convert the grams</u> of O to moles, so:

The next step is to divide all the mol values by the <u>smallest one</u>:



Therefore the formula is 
Answer:
See explanation
Explanation:
For this question, we have to remember the effect of an atom with high <u>electronegativity</u> as "Br". If the "Br" atom is closer to the carboxylic acid group (COOH) we will have an <u>inductive effect</u>. Due to the electronegativity of Br, the electrons of the C-H bond would be to the Br, then this bond would be <u>weaker</u> and the compound will be more acid (because is easier to produce the hydronium ion
).
With this in mind, for A in the last compound, we have <u>2 Br atoms</u> near to the acid carboxylic group, so, we will have a high inductive effect, then the C-H would be weaker and we will have <u>more acidity</u>. Then we will have the compound with only 1 Br atom and finally, the last compound would be the one without Br atoms.
In B, the difference between the molecules is the <u>position</u> of the "Br" atom in the molecule. If the Br atom is closer to the acid group we will have a <u>higher inductive effect</u> and more <u>acidity</u>.
See figure 1
I hope it helps!
Answer: Order of the elements from most reactive to least reactive is:
Mg > Zn > Fe > H > Cu
Explanation: Reactivity of the elements is the tendency of the elements to loose or gain electrons with ease.
As, all the given elements are metals, so the metals which will loose electrons easily will be more reactive. To study the reactivity of metals, we use reactivity series.
The metals which are more reactive are placed on the top of the reactivity series and which are less reactive are placed at the bottom.
Hence, the order of the elements from most reactive to least reactive is:
Mg > Zn > Fe > H > Cu
Reactivity series is attached below.