The brain is protected by the bones of the skull and by a covering of three thin membranes called meninges. The brain is also cushioned and protected by cerebrospinal fluid. This watery fluid is produced by special cells in the four hollow spaces in the brain, called ventricles.
3.2 x10000000
the correct answer is 3.2x 10⁷
The molar mass of a substance is the mass of one mole of that substance. Therefore, in order to calculate the mass that is present while the number of moles are known, we simply multiply the number of moles present by the molar mass. In the case of carbon dioxide, the molar mass is obtained by adding the mass of one carbon atom (12) and two oxygen atoms (32). The molar mass is 12 + 32 = 44. Therefore, the mass of carbon dioxide is 2.1 * 44 = 92.4 grams. The answer is D<span>.</span>
Answer:
Explanation:
HCl is strong acid, hence 0.04M of acid
= 0.057 M of H+
pH = -log [H+]
= -log [0.057]
= 1.244
Let the dissociation of trichloroacetic acid be:
HClO4 --> H^+ + ClO4^-
HA --> H+ + A-
0.072 - x x x
[H+] = 0.057 M
[HA] = 0.072 - 0.057
= 0.015 M
[H+] = [A-] = 0.057
Ka = [H+][A-]/[HA]
= (0.057^2)/(0.015)
= 0.217
= 0.22.
