<span>The "p" in pH and pOH stands for "negative logarithm of" and is used to make it easier to work with extremely large or small values. pH and pOH are only meaningful when applied to aqueous (water-based) solutions. </span>
Due to prescence of any impurity, there will be change in physical properties of any liquid.
Answer: Meniscus
Explanation: There is a condition on reading volumes. For concave meniscus read volume in the lower part and for convex meniscus read volume at the upper part.
Answer: 193 mg of theobromine are present in the sample.
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 theobromine
weigh = 180 g
of theobromine
weigh =
(1g=1000mg)
193 mg of theobromine are present in the sample.