•through brain mapping, what have scientists learned about the processing of pain in the brain?

Scientist learned through brain mapping that the processing of pain in the brain happens in different areas of the brain and every person processes pain in different ways. This is the reason why each individual has a different pain tolerance because we have the power to control it.

a)1.56 M

b) 0.376 M

c) 0.599 M

Explanation:

Step 1: Molarity

Molarity = Number of moles / volume in L

Number of moles = mass / Molar mass

(a) 7.49 g of methanol (CH3OH) in 1.50 * 10² mL of solution

Volume =  1.50 * 10² mL = 0.15 L

Molar mass of CH3OH = 32.04 g/mol

Number of moles CH3OH = 7.49 grams / 32.04 g/mol

Moles of CH3OH = 0.234 moles

Molarity CH3OH = 0.234 moles / 0.15 L

Molarity CH3OH = 1.56 M

(b) 9.18 g of calcium chloride (CaCl2) in 2.20 × 10² mL of solution:

Volume = 2.20 × 10² mL = 0.22L

Molar mass of CaCl2 = 110.98 g/mol

Number of moles CaCl2 = 9.18 grams /110.98 g/mol

Moles CaCl2 = 0.0827 moles

Molarity CaCl2 = 0.0827 moles / 0.22L

Molarity CaCl2 = 0.376 M

(c) 6.51 g of naphthalene (C10H8) in 85.2 mL of benzene solution:

Volume = 85.2 mL = 0.0852L

Molar mass of C10H8 = 128.17 g/mol

Number of moles C10H8 = 6.51 grams / 128.17 g/mol

Moles C10H8 = 0.051 moles

Molarity C10H8 = 0.051 moles / 0.0852 L

Molarity C10H8 = 0.599 M