Anonymous
Anonymous asked in Science & MathematicsChemistry · 9 years ago

# Lithium aluminum hydride (LiAlH4) and Sodium borohydride (NaBH4) are reducing agents. What is true about them?

A) the polarity of the B-H bond is greater than the Al-H bond, so LiAlH4 is a stronger reducing agent

B) the polarity of the B-H bond is greater than the Al-H bond, so LiAlH4 is a weaker reducing agent

C) the polarity of the B-H bond is less than the Al-H bond, so LiAlH4 is a stronger reducing agent

D) the polarity of the B-H bond is less than the Al-H bond, so LiAlH4 is a weaker reducing agent

Relevance
• 9 years ago

The key concept of this question is electronegativity. (http://en.wikipedia.org/wiki/Electronegativity)

Pauling electronegativity, H = 2.2, B = 2.04, Al = 1.61.

The fast (but not very accurate) estimation

The dipole of B-H bond is 2.2-2.04 = 0.16

The dipole of Al-H bond is 2.2-1.61 = 0.59

Therefore, Al-H is more polar than B-H bond or B-H is less polar than Al-H.

the possible choice is (C).

• 5 years ago

RE:

Lithium aluminum hydride (LiAlH4) and Sodium borohydride (NaBH4) are reducing agents. What is true about them?

A) the polarity of the B-H bond is greater than the Al-H bond, so LiAlH4 is a stronger reducing agent

B) the polarity of the B-H bond is greater than the Al-H bond, so LiAlH4 is a weaker reducing agent

C) the polarity of the B-H bond is less than the Al-H bond, so LiAlH4 is a stronger reducing...

Source(s): lithium aluminum hydride lialh4 sodium borohydride nabh4 reducing agents true them: https://biturl.im/eWZTK