A strong acid- strong base titration is performed using a phenolphthalein indicator. Phenolphtalein is chosen because it changes color in a pH range between 8.3 – 10. It will appear pink in basic solutions and clear in acidic solutions. ... It is known as the titrant.
Density is defined as the ratio of mass to the volume.
Density =
(1)
Mass of water = 10 grams
Mass of acetone = 10 grams
Density of water = 1 
Density of acetone = 0.7857 
Put the value of density of water and its mass in equation (1)
1
= 
Volume of water = 10 
Put the value of density of acetone and its mass in equation (1)
0.7857
= 
Volume of acetone = 12.72 
Thus, volume of acetone is more than volume of water because the density of acetone is lower.
The volume increases when the balloon temperature increases.
<u>Explanation:</u>
-10 F is converted into Kelvin as 249 K.
0°C is nothing but 0+ 273 = 273 K
And the room temperature is 25°C which is converted into Kelvin as 273 + 25 = 298 K.
249 K is below room temperature.
As per the Charles' law volume and temperature are directly proportional to each other, when the pressure of the gas remains constant.
V ∝ T
As the balloon temperature increases, the volume also increases.
Answer: There are
molecules in 63.00 g of 
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
of particles.
To calculate the moles, we use the equation:

1 mole of
contains =
molecules
Thus 3.5 moles of
contains =
molecules.
There are
molecules in 63.00 g of 
Answer: The correct answer is Hydrogen Fluoride.