I will solve this question assuming the reaction equation look like this:
<span>MnO2 + 4 HCl ---> MnCl2 + Cl2 + 2 H2O.
</span>
For every one molecule of MnO2 used, there will be one molecule of Cl2 formed. If the molecular mass of MnO2 is 87g/mol and molecular mass of Cl2 is <span> 73.0 g/mol, the mass of MnO2 needed would be:
Cl mass/Cl molecular mass * MnO2 molecular mass=
25g/ (73g/mol) * (87g/mol) * 1/1= 29.8 grams</span>
The pH of a buffer solution : 4.3
<h3>Further explanation</h3>
Given
0.2 mole HCNO
0.8 mole NaCNO
1 L solution
Required
pH buffer
Solution
Acid buffer solutions consist of weak acids HCNO and their salts NaCNO.
![\tt \displaystyle [H^+]=Ka\times\frac{mole\:weak\:acid}{mole\:salt\times valence}](https://tex.z-dn.net/?f=%5Ctt%20%5Cdisplaystyle%20%5BH%5E%2B%5D%3DKa%5Ctimes%5Cfrac%7Bmole%5C%3Aweak%5C%3Aacid%7D%7Bmole%5C%3Asalt%5Ctimes%20valence%7D)
valence according to the amount of salt anion
Input the value :
![\tt \displaystyle [H^+]=2.10^{-4}\times\frac{0.2}{0.8\times 1}\\\\(H^+]=5\times 10^{-5}\\\\pH=5-log~5\\\\pH=4.3](https://tex.z-dn.net/?f=%5Ctt%20%5Cdisplaystyle%20%5BH%5E%2B%5D%3D2.10%5E%7B-4%7D%5Ctimes%5Cfrac%7B0.2%7D%7B0.8%5Ctimes%201%7D%5C%5C%5C%5C%28H%5E%2B%5D%3D5%5Ctimes%2010%5E%7B-5%7D%5C%5C%5C%5CpH%3D5-log~5%5C%5C%5C%5CpH%3D4.3)
The graph is needed to answer this question.
Solubility may increase or decrease with temperature depending on the properties of the solute and the solvent.
It is quite common that the solubility of the ionic compounds, like KBr, in water increases with temperature.
Use your solubility curve for the KBr and you wiil see a line that starts at a solubility a little greater than 50 grams of the salt in 100 grams of water for temperaute 0°C and increase linearly until almost 100 grams of the salt in 100 grams of water at 100°C.
So, in this case you can affirm that the solubility of KBr increases with the temperature.
Answer: the second option: the solubility increases.
Answer:
190 mmHg
Explanation:
According to Dalton's law, in a mixture of ideal gases, each gas behaves independently of the other. Also, the total pressure is equal to the sum of the individual partial pressures.
The total pressure of the mixture is 470 mmHg , and the partial pressure of nitrogen is 280 mmHg. Then,
P = pO₂ + pN₂
pO₂ = P - pN₂
pO₂ = 470 mmHg - 280 mmHg
pO₂ = 190 mmHg
Given: C= 81.70% = 81.70g
H = 18.29% = 18.29g
<span>The number of moles is given by: n= Given mass (m)/Molar Mass (M)
</span>M of C = 12 g/mol
M of H = 1 g/mol
Thus, the number of moles of carbon = 81.70g / 12gmol= 6.83moles
and, the number of moles of hydrogen = 18.29/1g/mol = 18.29 moles
The ration of C moles with hydrogen :
H:C = 18.29moles/6.83moles= 2.67 ≈3
Thus, the empirical formula is C3H8