June 01, 2020, 09:41:54 AM
Forum Rules: Read This Before Posting

### Topic: How to find delta H when molar mass is unknown  (Read 4959 times)

0 Members and 1 Guest are viewing this topic.

#### deltamoles

• Guest
##### How to find delta H when molar mass is unknown
« on: December 04, 2005, 03:08:24 AM »
I am doing lab on doughnuts and calories.Experimentally we had to find the number of calories.(delta H)

My mass of water was 100g
delta t of water= 25-23=2

my mass of dougnut before was:6.24
and my after mass was 1.84
therefore delta m= -4.4

I started by finding the Q of water(Q=mc delta t )
which gave me 838 joules
which is 0.838 Kj

now i need to find delta h

the only formula i can think of to solve the question is
Qwater/delta M = delta H/molar mass
I know Qwater and delta m.But i have no molar mass.so i cant find delta H.

I need to find my Delta h and i cant think of how since i have 2 variables.Is there another way of finding delta h.Please help me out cuz like im stuck on this thing for an hour trying how to find delta h but i just cant find a way

thanx so much
pat

#### sdekivit

• Chemist
• Full Member
• Posts: 403
• Mole Snacks: +32/-3
• Gender:
• B.Sc Biomedical Sciences, Utrecht University
##### Re:How to find delta H when molar mass is unknown
« Reply #1 on: December 04, 2005, 04:03:45 AM »
you can also express H in J/g doughnut