Answer: I think you forgot to put the image up
Step by step explanation:
The question is incomplete, here is the complete question:
A 50 mL solution is initially 1.52% MgCl₂ by mass and has a density of 1.05 g/mL
What is the freezing point of the solution after you add an additional 1.37 g MgCl₂? (Use i = 2.5 for MgCl₂).
<u>Answer:</u> The freezing point of solution is -0.808°C
<u>Explanation:</u>
To calculate the mass of solution, we use the equation:
Density of solution = 1.05 g/mL
Volume of solution = 50 mL
Putting values in above equation, we get:
We are given:
Percentage of magnesium chloride in the solution = 1.52 %
Mass of magnesium chloride in the solution = 1.52 % of 52.5 g =
The equation used to calculate depression in freezing point follows:
To calculate the depression in freezing point, we use the equation:
Or,
where,
Freezing point of pure solution (water) = 0°C
i = Vant hoff factor = 2.5
= molal freezing point elevation constant = 1.86°C/m
= Given mass of solute (magnesium chloride) = [0.798 + 1.34] g = 2.138 g
= Molar mass of solute (magnesium chloride) = 95.2 g/mol
= Mass of solvent (water) = [52.5 - 0.798] g = 51.702 g
Putting values in above equation, we get:
Hence, the freezing point of solution is -0.808°C
The sulphate solutions came from a recycling LIBs waste cathode materials, which were done by previous research; their content is shown in Table 1 [18]. Sodium carbonate (Na2CO3) was purchased from Nihon Shiyaku Reagent, Tokyo, Japan (NaCO3, 99.8%), for the chemical precipitation. CO2 was purchased from Air Product and Chemical, Taipei, Taiwan (CO2 ≥ 99%), to carry out the hydrogenation–decomposition method. Dowex G26 was obtained from Sigma-Aldrich (St. Louis, MO, USA) and was used as a strong acidic cation exchange resin, to remove impurities. Multi-elements ICP standard solutions were acquired from AccuStandard, New Haven, Connecticut State, USA. The nitric acid (HNO3) and sulfuric acid (H2SO4) were acquired from Sigma-Aldrich (St. Louis, MO, USA) (HNO3 ≥ 65%) (H2SO4 ≥ 98%) The materials were analyzed by energy-dispersive X-ray spectroscopy (EDS; XFlash6110, Bruker, Billerica, MA, USA), X-ray diffraction (XRD; DX-2700, Dangdong City, Liaoning, China), scanning electron microscopy (SEM; S-3000N, Hitachi, Tokyo, Japan), and inductively coupled plasma optical emission spectrometry (ICP-OES; Varian, Vista-MPX, PerkinElmer, Waltham, MA, USA). In order to
Appl. Sci. 2018, 8, 2252 3 of 10
control the hydrogenation temperature and heating rate, a thermostatic bath (XMtd-204;
NO2- +7H+ + 6e->> NH3 + 2H2O ( N goes from +3 to -3)
<span>Al + 2 H2O >> AlO2- + 4H+ + 3e- </span>
<span>NO2- + 2Al + 2H2O >> NH3 + 2AlO2- + H+ </span>
<span>add OH- on the left and on the right </span>
<span>NO2- + 2 Al + H2O + OH- >> NH3 + 2 AlO2-</span>