Answer:
The standard enthalpy of formation of methanol is, -238.7 kJ/mole
Explanation:
The formation reaction of CH_3OH will be,

The intermediate balanced chemical reaction will be,
..[1]
..[2]
..[3]
Now we will reverse the reaction 3, multiply reaction 2 by 2 then adding all the equations, Using Hess's law:
We get :
..[1]
..[2]
[3]
The expression for enthalpy of formation of
will be,



The standard enthalpy of formation of methanol is, -238.7 kJ/mole
Answer:
<h2>The answer is 334 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
volume of ethanol = 423 cm³
density = 0.789 g/cm³
So we have
mass = 0.789 × 423 = 333.747
We have the final answer as
<h3>334 g</h3>
Hope this helps you
Answer:
275g
Explanation:
Depending on the molar mass you are given, you can use that to solve this.
(I'm going based on my science class' molar mass of sulphur being 32.07g/mol)
Starting off, the formula for finding moles is
n=m/M (moles = mass / molar mass)
We can manipulate this equation to solve for mass.
m=Mn
now fill in what we now.
m = 32.07*8.56
mass = 274.5192
Now round for significant digits (if you are needed to do)
mass = 275g
Answer:

Explanation:
1. Calculate the rate constant
The integrated rate law for first order decay is

where
A₀ and A_t are the amounts at t = 0 and t
k is the rate constant

2. Calculate the half-life
