Answer:
3 g/mL
Explanation:
We know that the density of an object can be measured by dividing its mass (g) to its volume (mL).
Formula
D=m/v
Given data:
Mass= 45 g
Volume= 15 mL
Now we will put the values in formula:
D=45 g/ 15 mL= 3 g/mL
Use the formula for second order reaction:

C = concentration at time t
C0 = initial conc.
k = rate constant
t = time
1st equation :

2nd Equation:

Find

from 1st equation and put it in 2nd equation:


k = 0.046
Answer: 4 hydrogens
Explanation:
This is what the structure will look like C=C. Remember that it's important that all structures have a complete octet. As it looks right now each carbon is sharing 4 valence electrons so each needs 2 more bonds to hydrogen complete its octet.