The answer is 3.5 × 10^-3
Answer:
B and E
Explanation:
These two options support the theory of plate tectonics.
Answer:
84 Joules are wasted per second.
Explanation:
An efficiency of 16% means 84% is wasted as heat energy.
Therefore;
For a 100W bulb;
Heat wasted = 84/100 × 100 W
= 84 W
Therefore;
84 W or 84 joules are wasted as heat per second
Answer:
94.4g/mol is molar mass of the unknown
Explanation:
Based on the freezing point depression equation:
ΔT = Kf*m*i
<em>Where ΔT is the depression in freezing point (1.87°C)</em>
<em>Kf is freezing point depression constant of water (1.86°Ckg/mol)</em>
<em>And i is Van't Hoff factor (1 for nonelectrolyte solutes)</em>
<em />
Replacing:
1.87°C = 1.86°CKg/mol*m*i
1.005mol/kg solvent = m
Using the mass of the solvent we can find the oles of the nonelectrolyte:
1.005mol/kg solvent * 0.4764kg = 0.479moles
Molar mass is defined as the ratio between mass of a substance in grams and moles, that is:
45.2g / 0.479mol =
<h3>94.4g/mol is molar mass of the unknown</h3>
The pKa of formic acid is 3.75. At pH of 5.00, b) [formate] > [formic acid].
Formic acid is a weak acid. Thus, together with its conjugate base (formate) they form a buffer system. We can calculate the pH of a buffer system using Henderson-Hasselbach's equation.
![pH = pKa + log \frac{[formate]}{[formic\ acid]} \\\\5.00 = 3.75 + log \frac{[formate]}{[formic\ acid]}\\\\\frac{[formate]}{[formic\ acid]} = 17.8](https://tex.z-dn.net/?f=pH%20%3D%20pKa%20%2B%20log%20%5Cfrac%7B%5Bformate%5D%7D%7B%5Bformic%5C%20acid%5D%7D%20%5C%5C%5C%5C5.00%20%3D%203.75%20%2B%20log%20%5Cfrac%7B%5Bformate%5D%7D%7B%5Bformic%5C%20acid%5D%7D%5C%5C%5C%5C%5Cfrac%7B%5Bformate%5D%7D%7B%5Bformic%5C%20acid%5D%7D%20%20%3D%2017.8)
As expected, at a pH above the pKa, the concentration of formate is higher than that of the formic acid.
The pKa of formic acid is 3.75. At pH of 5.00, b) [formate] > [formic acid].
Learn more: brainly.com/question/22821585