In order to answer this, we mus know the data for the heat of combustion of propane. This is an empirical data that you can search online. The heat of combustion is -2220 kJ/mol. The molar mass of propane of 44.1 g/mol. The solution is as follows:
ΔH = -2220 kJ/mol (1 mol/44.1 g)(1000g/1kg)(20 kg)
<em>ΔH = -1006802.721 kJ or -1 GJ</em>
You would expect 500 million atoms to be present. When a source experiences a half-life, it is a point in which atoms have degraded to half what they used to be in mass. 1/2(1 billion) = 500 million
Brainliest answer please
Answer:
Explanation:
The graduated cylinder contains 
of water
mL is a volume unit.
Water volume = 41.7 mL
The lead ball caused an increase of volume from 41.7 mL to 96.0 mL
The new volume is the lead ball volume plus the original water volume :
Final volume = Vlead ball+ Water original volume
This is actually true if we suppose that the lead ball is fully sunken in the water.
We always must consider that the volume difference is the volume that the sunken object is occupying in the water.
<h3>
Answer:</h3>
5.89 × 10^23 molecules of F₂
<h3>
Explanation:</h3>
The equation for the reaction between fluorine (F₂) and ammonia (NH₃) is given by;
5F₂ + 2NH₃ → N₂F₄ + 6 HF
We are given 66.6 g NH₃
We are required to determine the number of fluorine molecules
<h3>Step 1: Moles of Ammonia </h3>
Moles = Mass ÷ Molar mass
Molar mass of ammonia = 17.031 g/mol
Moles of NH₃ = 66.6 g ÷ 17.031 g/mol
= 3.911 moles
<h3>Step 2: Moles of Fluorine </h3>
From the equation 5 moles of Fluorine reacts with 2 moles of ammonia
Therefore,
Moles of fluorine = Moles of Ammonia × 5/2
= 3.911 moles × 5/2
= 9.778 moles
<h3>Step 3: Number of molecules of fluorine </h3>
We know that 1 mole of a compound contains number of molecules equivalent to the Avogadro's number, 6.022 × 10^23 molecules
Therefore;
1 mole of F₂ = 6.022 × 10^23 molecules
Thus,
9.778 moles of F₂ = 9.778 moles × 6.022 × 10^23 molecules/mole
= 5.89 × 10^23 molecules
Therefore, the number of fluorine molecules needed is 5.89 × 10^23 molecules
