Infrared waves travel at a speed of 3.00 x 10^8 m/s. What is the frequency of an infrared wave that has a vacuum wavelength of 5.5 micrometers?
(1 micrometer= 1x10^-6 m)
O 5.5 X 10^12 Hz
O 5.5 x 10^10 Hz
O 5.5 X 10^11 Hz
O 5.5 X 10^13 Hz

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.