1) c) It contains more solute dissolved than in a saturated solution at that temperature.
2) To calculate the solubility of NaCl at 20°C, we need to divide the mass of NaCl dissolved in the saturated solution by the mass of the solvent (water) in the solution.
Solubility = Mass of solute (NaCl) / Mass of solvent (water)
Given:
Mass of saturated solution = 27 gm
Residue after evaporation = 7 gm
Mass of NaCl dissolved = Mass of saturated solution - Residue after evaporation
= 27 gm - 7 gm
= 20 gm
Solubility = 20 gm / 27 gm
Using a calculator, the solubility of NaCl at 20°C is approximately 0.7407 or 28.57% (rounded to two decimal places).
Therefore, the answer is c) 28.57.
3) a) Nitrogen fixation.
Nitrogen fixation is the process by which atmospheric nitrogen (N2) is converted into a usable form, such as ammonia (NH3) or nitrates (NO3-). This process is primarily carried out by nitrogen-fixing bacteria, which convert nitrogen gas into ammonia through biological or industrial processes.
4) a) sinA - cosA = tanA
Given that tanA = 1, we can substitute tanA into the equation:
sinA - cosA = 1
5) The arithmetic mean is the average of two numbers, while the geometric mean is the square root of their product.
The arithmetic mean between 3 and 27 is (3 + 27) / 2 = 30 / 2 = 15.
The geometric mean between 3 and 27 is √(3 × 27) = √81 = 9.
The difference between the arithmetic mean and geometric mean is 15 - 9 = 6.
Therefore, the answer is b) 6.
6) c) a = 0, b = 0.
If a + ib = 0, it implies that both the real part (a) and the imaginary part (b) are zero.
♥️
