Heat require to boil 15.6 g iron from 122 C0to 355 C0 whereas,

Where, m is mass of iron
s is specific heat of iron
d T is change in temperature in celcius

If
1 cal = 4.2 J
Then,

Thus 0.389 k cal of enrgy is required by a 15.6 g Fe to reach to 355 C^0
Answer:
False. Chemical changes are always physical changes
Answer:
1.40 atm is the pressure for the gas
Explanation:
An easy problem to solve with the Ideal Gases Law:
P . V = n . R .T
T° = 370K
V = 17.3L
n = 0.8 mol
Let's replace data → P . 17.3L = 0.8mol . 0.082L.atm/mol.K . 370K
P = (0.8mol . 0.082L.atm/mol.K . 370K) / 17.3L = 1.40 atm
CH3NH2 can only have as many hydrogen bonds as hydrogen bonding sites in the molecule. CH3NH2 has two N−H bonds and a lone pair of electrons on the nitrogen atom. Therefore, CH3NH2 can form three hydrogen bonds with water.