1 mole of any substance contains 6.022 × 1023 particles.
⚛ 6.022 × 1023 is known as the Avogadro Number or Avogadro Constant and is given the symbol NA
N = n × NA
· N = number of particles in the substance
· n = amount of substance in moles (mol)
· NA = Avogardro Number = 6.022 × 10^23 particles mol-1
For H2O we have:
2 H at 1.0 each = 2.0 amu
1 O at 16.0 each = 16.0 amu
Total for H2O = 18.0 amu, or grams/mole
It takes 18 grams of H2O to obtain 1 mole, or 6.02 x 1023 molecules of water. Think about that before we answer the question. We have 25.0 grams of water, so we have more than one mole of water molecules. To find the exact number, divide the available mass (25.0g) by the molar mass (18.0g/mole). Watch how the units work out. The grams cancel and moles moves to the top, leaving moles of water. [g/(g/mole) = moles].
Here we have 25.0 g/(18.0g/mole) = 1.39 moles water (3 sig figs).
Multiply 1.39 moles times the definition of a mole to arrive at the actual number of water molecules:
1.39 (moles water) * 6.02 x 1023 molecules water/(mole water) = 8.36 x 1023 molecules water.
That's slightly above Avogadro's number, which is what we expected. Keeping the units in the calculations is annoying, I know, but it helps guide the operations and if you wind up with the unit desired, there is a good chance you've done the problem correctly.
N = n × (6.022 × 10^23)
1 grams H2O is equal to 0.055508435061792 mol.
Then 23 g of H2O is 1.2767 mol
To calculate the number of particles, N, in a substance:
N = n × NA
N = 1.2767 × (6.022 × 10^23)
N= 176.26
N=
Holding
temperature and pressure constant
<span>the
most important feature in determining the phase of a given organic compound is
pressure. ransfers of organic compounds
between phases are controlled by molecular interactions (intermolecular bonding)
in the two phases between which transfer is occurring. This is governed
by temperature and pressure</span>
Answer:
The answer is 2.20 M
Explanation:
This is because ammonia has a pH of 11.8 and if you take 14-11.8 it equals 2.2 so the answer is 2.20 M
Another product: CO₂
<h3>Further explanation</h3>
Given
Reaction
2C₄H₁₀ + 13O₂⇒ 8__+ 10H₂O
Required
product compound
Solution
In the combustion of hydrocarbons there can be 2 kinds of products
If there is excess Oxygen, you will get Carbon dioxide(CO₂) and water in the product
If Oxygen is low, you'll get Carbon monoxide(CO) and water
Or in other ways, we can use the principle of the law of conservation of mass which is also related to the number of atoms in the reactants and in the products
if we look at the reaction above, there are C atoms on the left (reactants), so that in the product there will also be C atoms with the same number of C atoms on the left
2C₄H₁₀ + 13O₂⇒ 8CO₂+ 10H₂O
