True, both of the red and white phosphorus is a pure substance.
Both red and white phosphorus is made of phosphor element but they have a different structure which causes them to have a different color. This phenomenon called allotropes when a chemical element has two or more different form.They are not compounds as they are only made of phosphorus. A compound should be made by at least two different elements.
Answer: the reliability will be worse
Explanation:
Suppose we used 0.5 M NaOH to titrate our vinegar sample instead of 0.1 M.
Now by using 0.5M instead of 0.1M we are increasing the concentration of NaOH,
We know that the moles used = Volume x concnetration.
so for the same no of moles, if the concentration increases, the volume decreases.
Hence it will consume less NaOH.
now Since the volume decreases, the titration volume of less number will increase the % error.
Therefore the reliability will be worse.
a. t=0.553 s
b. vox(horizontal speed) = 3.62 m/s
<h3>Further explanation</h3>
Given
h = 1.5 m
x = 2 m
Required
a. time
b. vo=initial speed
Solution
Free fall motion
a. h = 1/2 gt²(vertical motion=h=voyt+1/2gt²⇒voy = 0)

t = √2h/g
t = √2.1.5/9.8
t=0.553 s
b. x=vox.t(horizontal motion)

vox=x/t
vox=2/0.553
vox=3.62 m/s
1.question, 2.observe, 3.hypothesize, 4.experiment 5.conclusion, 6. record.