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=
Answer:
Hello! Some household items that are electroplated include kitchenware, such as metal pots and pans, door handles, mobile phones, and coins. An electroplated object is coated by electrolytic deposition with chromium, silver, or another metal.
Answer:
The answer to your question is letter C.
Explanation:
Reaction
Potassium hydroxide = KOH
Barium chloride = BaCl₂
Potassium chloride = KCl
Barium hydroxide = Ba(OH)₂
KOH + BaCl₂ ⇒ KCl + Ba(OH)₂
Reactant Elements Products
1 K 1
1 Ba 1
2 Cl 1
1 H 2
1 O 2
The reaction is unbalanced
2KOH + BaCl₂ ⇒ 2KCl + Ba(OH)₂
Reactant Elements Products
2 K 2
1 Ba 1
2 Cl 2
2 H 2
2 O 2
Now, the reaction is balanced
The question is asking us to determine what gives the Amethyst its purplish color. Amethyst colors range from light to dark purple. The most highly regarded are the transparent deep purple colors. Amethyst ( chemical formula: Si O2 ) is the purple variety of the mineral Quartz.The pure Quartz is often colorless. Amethyst gets its purplish color because of the presence of Iron ( Fe ) and other impurities in the gem. Answer: C. Iron.<span /><span />
To balance it, it would be N2 + 3H2 ------> 2NH3.
for c) it would be 2N2 + 6H2 -------> 4NH3
