Alow-sodium vegetable juice contains 12 mg na+ in each 10-oz (1 oz = 29.57ml) serving. what is the concentration of na+ ion?
[na+] = 1.7 x 10-5 m
[na+] = 7.1 x 10-3 m
[na+] = 7.1 x 10-5 m
[na+] = 1.7 x 10-3 m

did anyone actually do this? like if anyone has submitted this i rly need .

the answer is 0.42 is that is an option. this question provides no info

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.