Answer:
please mark brainlest and it's Procedure 1: One of the products was a gas that escaped into the air.
Procedure 2: A gas from the air reacted with one of the other reactants
Explanation:
the gas ca evaporate so it would'nt be a or c and b dosent make sense.
Answer:
- From octane: 
- From ethanol: 
Explanation:
Hello,
At first, for the combustion of octane, the following chemical reaction is carried out:

Thus, the produced mass of carbon dioxide is:

Now, for ethanol:


Best regards.
Let us assume that the ring is a size 7 ring, which has a circumference of 54.3 millimeters. Converting this to centimeters, the circumference of the ring is:
54.3 mm = 5.43 cm
Now, we determine the number of gold atoms that will be present in this:
5.43 / 1 x 10⁻⁹
There will be 5.43 x 10⁹ atoms
We now determine the number of moles this is by:
one mole = 6.02 x 10²³ atoms
Moles = 5.43 x 10⁹ / 6.02 x 10²³
Moles = 9.01 x 10⁻¹⁵ moles
The molar mass of gold is 197 g/mol
The mass is 9.01 x 10⁻¹⁵ * 197
The mass of the strand is 1.76 x 10⁻¹² grams
Answer:
A hypothesis is a possible explanation for a set of observations or an answer to a scientific question. A hypothesis must be testable and measurable.
Explanation: