How many significant figures should the result have 2.524 g (5.1 • 106 g)

Two  

Step-by-step explanation:

In multiplication problems, your answer can have no more significant figures than the number with the fewest significant figures.

Start with the calculation inside parentheses:

5.1 × 10.6 = 54.060 000 00 (by my calculator)

There are three significant figures in 10.6, but only two in 5.1.

In this were a number you had to report, you would round to two significant figures and report the answer as 54.

54.060 000 00 → 54 (to two significant figures)

However, you must multiply this intermediate answer by 2.524.

Therefore, you multiply the number in the calculator by 2.524 and get

54.060 000 00 × 2.524 = 136.447 4400

NOW, you round to two significant figures and report the answer as 140.

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

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.