Answer: The answer is True
Explanation:
The answer is true because Walking, biking, and reusing paper helps the economy
NH3 is a molecule with a nitrogen atom in the middle surrounded by 3 hydrogen atoms bonded covalently. Nitrogen has 5 valence electrons so, it will form sigma bonds (sp3 hybrid orbitals) with each of the hydrogen atom. The remaining lone pair electrons will be situated above the atom. You ca look at this image I've pulled from Google.
Answer:
0,171 M NaCl and 0,168 m NaCl
Explanation:
Molarity (M) is an unit of chemical concentration that relates moles of solute per liters of solution and molality (m) is another unit of chemical concentration that relates moles of solute per kg of solution.
For a solution of 10g/L of NaCl the molarity is:
10g/L NaCl× = 0,17 moles/L of NaCl≡ 0,171 M NaCl
For molality you can know that in 1 L you have 0,17 moles of NaCl.
The kg of solution are:
0,010 kg of NaCl (solute) + 1 kg of solvent (Water, 1L of water is 1 kg) = 1,01 kg of solution.
Thus, molality of 10 g/L NaCl solution is:
= 0,168 m NaCl
I hope it helps!
Answer:
The recovery of pure caffeine is 67.3% of the original, crude sample.
Explanation:
Step 1: Data given
Mass of pure caffeine = 1.69 grams
Original mass of sample = 2.51 grams
Step 2: What is the percent recovery of pure caffeine from crude?
Percentage = (mass of recovery / original mass) *100%
Percentage = (1.69 grams/2.51 grams) *100%
Percentage = 67.3 %
The recovery of pure caffeine is 67.3% of the original, crude sample.
100.0g x 4.184J/g/°C x 78°C ΔT = 32,645.2 Joules.