Answer:
The answer is A. Polar covalent; negatively
Explanation:
Hydrogen bonds form between molecules containing polar covalent bond the hydrogen bond is been a hydrogen atom of one molecule and a partially negative charged atom of another.
Example 
(water):- It contain a slight positive charge on one side and a slight negative charge on the other.
Your question is incomplete. However, I found a similar problem fromanother website as shown in the attached picture.
To solve this problem, you must know that at STP, the volume for any gas is 22.4 L/mol. So,
Moles O₂: 156.8 mL * 1 L/1000 mL* 1 mol/22.4 L = 0.007 moles
Mass calcium: 0.007 mol O₂ * 2 mol Ca/1 mol O₂ * 40 g/mol Ca =
<em> 0.56 g Ca</em>
Answer:
The correct answer is - 2770000 cm.
Explanation:
1 kilometer = 1000 meter
1 meter = 100 centimeter
1 kilometer = 100*1000 cm
1 km = 100000 cm.
then,
27.7 kilometers = 2.77 × 10^6 centimeters
So, 27.7 kilometers = 27.7 × 100000
= 2.77 × 106 or 2770000 centimeters.
Answer:
pH = 11.05
Explanation:
It is possible to answer this question using Henderson-Hasselbalch formula:
pH = pka + log₁₀ [A] / [HA⁺]
Where A in this case is weak base (dimethylamine) and conjugate acid (HA⁺) is dimethylamine hydrochloride.
As Ka= Kw / Kb = 1x10⁻¹⁴ / 7.4x10⁻⁴ = 1.35x10⁻¹¹ And pKa is -log Ka = <em>10.87 </em> pH of the solution is:
pH = 10.87 + log₁₀ [0.600] / [0.400]
<em>pH = 11.05</em>
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I hope it helps!
