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HF is a weak acid with a Ka
--
6.6x10-4
This means after HF is dissolved in water, you have
Select one:
O a. no molecules with all ions
b. few molecules with mostly H+ ions
Oc.
a non electrolyte
d. mostly molecules with few H+ ions
e.
all molecules with no H+ ions
Clear my choice
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(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.