This is molarity: moles of solute/liters of solution. (Not molality)
1. Plug in what we know:
500 mL = 0.5 L
0.80 = moles/0.5
0.80*0.5 = moles
moles = 0.4
2. NaOH is given as 40 g/mole, so calculate the grams:
0.4 * 40 = 16 grams
answer: 16 grams
Enthalpy change is the term given to the concentration of the heat absorbed or evolved in a reaction carried out at a constant pressure. It is given by the symbol ΔH.
Enthalpy change = m (Cwater × dT + Hvap + Csteam × dT
dHvap = 40.67 kJ/mol = 40.67 × 103/18 = 2259.4 J/g
Enthalpy change = 5.00 [4.18 × (100-14) + 2259.4 + 1.84 × (115-100)]
= 13232.4 J
The optimal pH is 6.9. The pancreatic amylase is a hydrolase secreted by pancreas and will go into the alimentary canal. The working environment has a pH of 6.9. So the optimal pH for the enzyme needs to be 6.9.
First, we have to get how many grams of C & H & O in the compound:
- the mass of C on CO2 = mass of CO2*molar mass of C /molar mass of CO2
= 0.5213 * 12 / 44 = 0.142 g
- the mass of H atom on H2O = mass of H2O*molar mass of H / molar mass of H2O
=0.2835 * 2 / 18 = 0.0315 g
- the mass of O = the total mass - the mass of C atom - the mass of H atom
= 0.3 - 0.142 - 0.0315 = 0.1265 g
Convert the mass to mole by divided by molar mass
C(0.142/12) H(0.0315/2) O(0.1265/16)
C(0.0118) H(0.01575) O(0.0079) by dividing by the smallest value 0.0079
C1.504 H3.99 O1 by rounding to the nearst fraction
C3/2 H4/1 )1/1 multiply by 2
∴ the emprical formula C3H8O2
The prediction is that B. The electrons will flow to the zinc anode where a negative charge will build up and eventually halt the reaction.
<h3>What is zinc?</h3>
This is known as a chemical element, of the periodic table, that is essential to life and is one of the most widely used metals. Zinc is of considerable commercial importance.
Without the salt bridge, positive and negative charges will build up around the electrodes causing the reaction to stop.
Hence, we know that the purpose of the salt bridge is to keep the solutions electrically neutral and allow the free flow of ions from one cell to another.
Read more about<em> zinc</em> here:
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