There chemical reactions that can realise or absorb gas to the atmosphere. This means it is harder or impossible to measure it with normal weighing devices and normal taring equipment. As a principal in chemical reactions we have conservation of mass.
Change occurs in the density of the gummy bear to change if we soaked it in isopropanol.
<h3>Effects on density by soaking isopropanol</h3>
We expect the density of the gummy bear to change if we soaked it in isopropanol because the gummy bear absorb the liquid which increase its density due to increasing weight of the gummy bear.
If a substance gains weight then its density also increases and we know that when the gummy bear was soaked in the isopropanol then its weight increases so its density is also changes so we can conclude that change occurs in the density of the gummy bear to change if we soaked it in isopropanol.
A pH indicator works in a better way in a range of pH = pKa ± 1. That means we need to determine the pKa of the indicator propyl red to find the range over which it change its color. That is:
pKa = -log Ka
pKa = -log 3.3x10⁻⁶
pKa = 5.48
That means the range over propyl red will change from yellow to red or vice versa is: