Answer:
Explanation:
Molarity of NaOAc needed
Using the Henderson-Hasselbalch Equation calculate base molarity needed given [HOAc] = 1.00M and pKa(NaOAc) = 4.75 and [HOAc] = 1.00m.
pH = pKa + log [NaOAc]/[HOAc]
5.00 = 4.75 + log[NaOAc]/[1.00M]
5.00 - 4.75 = log [NaOAc] - log[1.00M]
log [NaOAc] = 0.25 => [NaOAc] = 10⁰·²⁵ M = 1.78
Given 10ml of HOAc, how much (ml) 1.78M NaOAc to obtain a buffer pH of 5.00.
Determine Volume of Base Needed
(M·V)acid = (M·V)base => V(base) = (M·V)acid / (M)base
Vol (NaOAc) needed = (1.00M)(0.010L)/(1.78M) = 0.0056 liter = 5.6 ml.
Checking Results:
5.00 = 4.75 + log [1.78M]/[1.00M] = 4.75 + 0.25 = 5.00 QED.
Answer: hot
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and the system will be cold and surroundings will be hot.
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and the system will be hot and surroundings will be cold.
As heat is absorbed, the reaction is endothermic and the system will feel hot.
Answer: 48.95g
Explanation:
no. of moles of Cl2 = 39/(2*35.5) = 0.55 mol
no. of moles of Al = 34/27 = 1.26 mol
hence, aluminium is in excess so we'll do calculation using no. of moles of Cl2 as it will be the only reactant to be used up completely. So,
no of moles of AlCl3 = 2/3 * (0.55) = 0.367 mol
hence amount of AlCl3 = 0.367 * (27+3*35.5) = 48.95g
The water will started boiling and the pasta is going to start like melting so it can get a soft and smooth texture so you can eat it.
Due to energy being a reactant instead of a product, the process is endothermic. The system must absorb a quantity of energy before it can react, so it must be an endothermic system.
