Calculate the energy needed to raise the temperature of 18.0g of water from 10.0C to 40.0C. The specific heat of water is 4.18 J/gC. *

The energy needed to raise the temperature 18.0 grams of water is from 10.0°C to 40.0°C is 2,257.2 Joules.

Explanation:

Where:

Q = heat absorbed  or heat lost

c = specific heat of substance

m = Mass of the substance

ΔT = change in temperature of the substance

: Initial and final temperature of the substance

We have mass of water = m = 18.0 g

Specific heat of water= c = 4.18 J/g°C

Initial and final temperature of the water=

Final temperature of the water=

Heat absorbed by the water:

The energy needed to raise the temperature 18.0 grams of water is from 10.0°C to 40.0°C is 2,257.2 Joules.

d. temperate deciduous forest

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