Answer:
2.76 gram
Explanation:
2AI + 6HCl → 2AlCl3 + 3H2
- get the mol of aluminum => n = m / M = 25 / 27 = 0.925 (mol)
- get the ratio mol of Hydro => nH2 = 0.925 * 3 / 2 = 1.38 (mol)
- get weight of hydro mH2 = n x M = 1.38 x 2 = 2.76 (gram)
<u>Answer:</u> The molarity of stock solution of luminol is 1.055 M
<u>Explanation:</u>
To calculate the molarity of solution, we use the equation:
![\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}](https://tex.z-dn.net/?f=%5Ctext%7BMolarity%20of%20the%20solution%7D%3D%5Cfrac%7B%5Ctext%7BMass%20of%20solute%7D%5Ctimes%201000%7D%7B%5Ctext%7BMolar%20mass%20of%20solute%7D%5Ctimes%20%5Ctext%7BVolume%20of%20solution%20%28in%20mL%29%7D%7D)
Given mass of luminol = 14.0 g
Molar mass of luminol = 177 g/mol
Volume of solution = 75.0 mL
Putting values in above equation, we get:
![\text{Molarity of stock solution}=\frac{14\times 1000}{177\times 75.0}\\\\\text{Molarity of stock solution}=1.055M](https://tex.z-dn.net/?f=%5Ctext%7BMolarity%20of%20stock%20solution%7D%3D%5Cfrac%7B14%5Ctimes%201000%7D%7B177%5Ctimes%2075.0%7D%5C%5C%5C%5C%5Ctext%7BMolarity%20of%20stock%20solution%7D%3D1.055M)
Hence, the molarity of stock solution of luminol is 1.055 M
Answer:
=384.48°C
Explanation:
Change in enthalpy is negative because heat energy is lost to the surroundings.
Change in enthalpy= mass ×specific heat capacity× Change in temperature.
ΔH=MC∅
m=14grams
C of iron= 0.45 J/g°C
∅=?
186.0J= 14.0g × 0.45J/g°C×∅
186=6.3∅
∅=29.5°C
Final temperature= 414.0°C - 29.52°C
=384.48°C