Density is calculated using the following rule:
density = mass / volume
therefore:
mass = density * volume
mass of Hg = 13.6 * 60.2 = 818.72 grams
From the periodic table:
molar mass of Hg = 200.59 grams
number of moles = mass / molar mass
number of moles of Hg = 818.72 / 200.59 = 4.08 moles
each mole contains Avogadro's number of atoms.
Therefore,
number of atoms in the given sample = 4.08 * 6.022 * 10^23
= 2.456976 * 10^24 atoms
Answer:
To increase surface area of the platinum electrode which results in superior quality and action of the electrodes as opposed to normal platinum electrodes.
Explanation:
Platinization of Platinum is the process of covering platinum electrode with a layer of platinum black. Platinum black is a finally divided form of platinum, optimized for catalysing the addition of hydrogen to unsaturated organic compound. This increases the surface area of the platinum electrodes and therefore exhibits action superior to that of normal electrodes.
Reactions of Ethyl-3-pentenoate with all given reagents are given below.
Reaction with H₂ / Pd:
The non-polar double bond present in Ethyl-3-pentenoate is reduced to saturated chain. This reagent can not reduce the carbonyl group.
Reaction with NaBH₄: Sodium Borohydride is a weak reducing agent at compared to LiAlH₄. It can only reduce aldehydes and Ketones to corresponding alcohols.
Reaction with LiAlH₄: Lithium Aluminium hydride is a strong reducing agent. It can reduce all types of carbonyl compounds to corresponding alcohols, But, it can not reduce non-polar double bonds like alkenes and alkynes.
Result: The correct answer is
Option-A (Highlighted RED below).
Mass of lead (II) chromate is 51 g. The molecular formula is
and its molar mass is 323.2 g/mol
Number of moles can be calculated using the following formula:

Here, m is mass and M is molar mass.
Putting the values,

Therefore, number of moles of lead (II) chromate will be 0.1578 mol.
Answer: The millimoles of sodium carbonate the chemist has added to the flask are 256
Explanation:
Molarity is defined as the number of moles dissolved per liter of the solution.
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of
solution = 1.42 M
Volume of solution = 180.0 mL
Putting values in equation 1, we get:

Thus the millimoles of sodium carbonate the chemist has added to the flask are 256.