Answer:
Sand comes from many locations, sources, and environments. Sand forms when rocks break down from weathering and eroding over thousands and even millions of years. Rocks take time to decompose, especially quartz (silica) and feldspar .
Explanation:
Answer:
a) Molarity KCl = 0.755 M
b) molality HNO = 5.09 m
Explanation:
- Formality (F) = moles sto / L sln
- Molarity (M) = # dissolved specie / L sln
- molality (m) = moles sto / Kg ste
- %p/p = ( g sto / g ste ) * 100
a) KCl ↔ K+ + Cl-
moles KCL:
⇒ 20 g KCl * ( mol / 74.6 g ) = 0.268 mol KCl
⇒ F = 0.268 mol KCl / 0.355 L = 0.755 F
⇒ M [ K+ ] = 1 * ( 0.755) = 0.755 M
b) 24% HNO:
calculation base: 1 g solution:
⇒24 = ( g sto / g sln) * 100
⇒ 0.24 = g sto / 1
⇒ g sto = 0.24g
⇒g sln = 1 - 0.24 = 076g sln
⇒Kg ste = 0.76 g * ( Kg / 1000g ) = 7.6 E-4 Kg ste
moles sto (HNO):
⇒ 0.24g * ( mol / 62.03g) = 3.869 E-3 moles HNO
⇒ m = 3.869 E-3 moles HNO / 7.6 E-4 Kg sln
⇒ m = 5.09 mol/Kg
Answer:
The mass of water is 36 g.
Explanation:
Mass of hydrogen = 4 g
Mass of water = ?
Solution:
First of all we will write the balance chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen = mass / molar mass
Number of moles of hydrogen = 4 g/ 2 g/mol
Number of moles of hydrogen = 2 mol
Now we compare the moles of water with hydrogen from balance chemical equation.
H₂ : H₂O
2 : 2
Mass of water = moles × molar mass
Mass of water = 2 mol × 18 g/mol
Mass of water = 36 g
If the water oxygen is in excess than mass of water would be 36 g.
Answer:
k = 4.85 x 10⁻³ / s
Explanation:
For a first order reaction we have two very important equations we need to memorize:
ln ( N/N₀ ) = -kt
and,
0.693/ k = t₁/₂
where k is the rate constant and t i is the halflife which can be derived from the first equation.
0.693/ k = t₁/₂ ⇒ k = 0.693 / t₁/₂
k = 0.693 / 143 s = 4.85 x 10⁻³ / s
