Answer:
- The molarity of the student's sodium hydroxide solution is 0.0219 M
Explanation:
<u>1) Chemical reaction.</u>
a) Kind of reaction: neutralization
b) General form: acid + base → salt + water
c) Word equation:
- sodium hydroxide + oxalic acid → sodium oxalate + water
d) Chemical equation:
- NaOH + H₂C₂O₄ → Na₂C₂O₄ + H₂O
b) Balanced chemical equation:
- 2NaOH + H₂C₂O₄ → Na₂C₂O₄ + 2H₂O
<u>2) Mole ratio</u>
- 2mol Na OH : 1 mol H₂C₂O₄ :1 mol Na₂C₂O₄ : 2 mol H₂O
<u>3) Starting amount of oxalic acid</u>
- mass = 28 mg = 0.028 g
- molar mass = 90.03 g/mol
- Convert mass in grams to number of moles, n:
n = mass in grams / molar mass = 0.028 g / 90.03 g/mol = 0.000311 mol
<u>4) Titration</u>
- Volume of base: 28.4 mL = 0.0248 liter
- Concentration of base: x (unknwon)
- Number of moles of acid: 2.52 mol (calculated above)
- Proportion using the theoretical mole ratio (2mol Na OH : 1 mol H₂C₂O₄)
That means that there are 0.000622 moles of NaOH (solute)
<u>5) Molarity of NaOH solution</u>
- M = n / V (liter) = 0.000622 mol / 0.0284 liter = 0.0219 M
That is the correct number using <em>three signficant figures</em>, such as the starting data are reported.
Answer:
Evaporation
Explanation:
Water in the ocean, rivers, lakes, etc. is part of the hydrosphere, and when that water evaporates it enters the atmosphere
Kinetic
Gravitational
Sound
Elastic
Motion
Light
Radiant
Electrical
Answer:
Initial temperature, T1 = 99.4 Kelvin
Explanation:
<u>Given the following data;</u>
- Initial volume, V1 = 65.8 Litres
- Final temperature, T2 = 200 Kelvin
- Final volume, V2 = 132.4 Litres
To find the initial temperature (T1), we would use Charles' law;
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles' law is given by the formula;
Making T1 as the subject formula, we have;
Substituting the values into the formula, we have;
<em>Initial temperature, T1 = 99.4 Kelvin</em>
Answer:
The term temperature refers to the average amount of heat or the motion energy of particles in a substance. It measures the hotness and coldness of a substance. If an object has particles that move very fast, then it has a high temperature.
Temperature is different from the term thermal energy. Thermal energy is the total motion energy of particles in a substance. The movement of particles is always dependent on their number. If an object contains many particles, then it has greater thermal energy.
On the other hand, Heat is the energy that is involved in the movement of particles between objects that have different temperatures, particularly from an object with a high temperature to an object with a low temperature.
