H=(2x1.008)=2.016
O= 15.999
15.999
+ 2.016
______
18.015 g/mol :)
Answer:
There are multiple ways to check mass but I'll tell you one. Look below
Explanation:
One easy way of checking atomic mass is by adding protons and neutrons.
For example:
We have 5 protons and 4 neutrons.
5+4=9
I hope this helps (:
Answer:

Explanation:
Hello!
In this case, since the equation we use to model the heat exchange into the calorimeter and compute the heat of reaction is:

We plug in the mass of water, temperature change and specific heat to obtain:

Now, this enthalpy of reaction corresponds to the combustion of propyne:

Whose enthalpy change involves the enthalpies of formation of propyne, carbon dioxide and water, considering that of propyne is the target:

However, the enthalpy of reaction should be expressed in kJ per moles of C3H4, so we divide by the appropriate moles in 7.00 g of this compound:

Now, we solve for the enthalpy of formation of C3H4 as shown below:

So we plug in to obtain (enthalpies of formation of CO2 and H2O are found on NIST data base):

Best regards!
Answer:
I think that it might be 2.7
Explanation: