The hardest form of carbon is diamond.
Answer:
0.2mol/dm³
Explanation:
Given parameters:
Mass of Na₂CO₃ = 10.6g
Volume of solution = 500mL
Unknown:
Molarity of solution = ?
Solution:
The molarity of a solution can be determined using the expression below:
Molarity =
Number of moles =
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = = 0.1mol
Convert mL to dm³;
500mL will give 500 x 10⁻³dm³or 0.5dm³
So;
Molarity = = 0.2mol/dm³
Answer:
Identify each equation as a composition reaction, a decomposition reaction, or neither.
Fe2O3 + 3 SO3 → Fe2(SO4)3
NaCl + AgNO3 → AgCl + NaNO3
(NH4)2Cr2O7 → Cr2O3 + 4 H2O + N2
Solution
In this equation, two substances combine to make a single substance. This is a composition reaction.
Two different substances react to make two new substances. This does not fit the definition of either a composition reaction or a decomposition reaction, so it is neither. In fact, you may recognize this as a double-replacement reaction.
A single substance reacts to make multiple substances. This is a decomposition reaction.
Test Yourself
Identify the equation as a composition reaction, a decomposition reaction, or neither.
C3H8 → C3H4 + 2 H2
Explanation:
I hope I help :)))
Answer:
49.0g/mol is molar mass of X
Explanation:
<em>551mg of X are dissolved in 100g of benzonitrile</em>
<em>Freezing point of solution: -13.4°C</em>
The freezing point depression of a solution (Colligative property) follows the equation:
ΔT = Kf*m*i
<em>Where ΔT is change in freezing point from the pure solvent (Benzonitrile: -12.8°C) to the solution (-13.4°C)</em>
<em>Kf is freezing point depression of benzonitrile: 5.34°C/m</em>
m is molality of the solution (Moles X / kg of benzonitrile)
And i is Van't Hoff factor (1 for any solute in benzonitrile)
ΔT = -12.8°C - (-13.4°C) = 0.6°C
Solving for molality of the solution:
ΔT = Kf*m*i
0.6°C = 5.34°C/m*m*1
0.1124m = molality of the solution
Moles of X are:
0.1124mol/kg benzonitrile * 0.1kg benzonitrile = 0.01124 moles X
In 551mg = 0.551g:
Molar mass:
0.551g / 0.01124mol =
49.0g/mol is molar mass of X