Molar mass is the ratio of the mass to that amount of the substance. The mass of the barium nitrate in the formula unit is 23.0 grams.
<h3>What is mass?</h3>
The mass of a substance is the product of the molar mass of the compound and the number of moles of the compound.
Given,
Molar mass of barium nitrate = 261.35 g/mol
If,
have a mass of 261.35 g/mol then,
formula units will have a mass of,

Therefore, option C. 23.0 gm is the mass of barium nitrate.
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The rate constant for 1st order reaction is
K = (2.303 /t) log (A0 /A)
Where, k is rate constant
t is time in sec
A0 is initial concentration
(6.82 * 10-3) * 240 = log (0.02 /A)
1.63 = log (0.02 /A)
-1.69 – log A = 1.63
Log A = - 0.069
A = 0.82
Hence, 0.82 mol of A remain after 4 minutes.
<h3>Further explanation
</h3>
In general, some people equate mass and weight.
Mass is one of the principal quantities, which is related to the matter , whereas weight is a force that leads to the center of the earth (Earth's gravitational force)
Steps that can be taken to find the mass :
- 1. Weigh graduated cylinder (empty)
- 2. Pour the alcohol in the beaker into the graduated cylinder to the level of 40 ml
- 3. Weigh again graduated cylinder + poured alcohol
- 4. mass of alcohol 40 ml = mass in 3rd step - mass in the first step
Protons and neutrons are in the nucleus of an atom, whereas electrons are present in orbitals, or shells, outside an atom. Electrons are negatively charged, protons positive, and neutrons have no charge, or are neutral. Protons and neutrons have a relative mass of approx. 1 Atomic Mass Unit (amu), whereas electrons have a relative mass of approx 0.00055 amu.