The rate constant : k = 9.2 x 10⁻³ s⁻¹
The half life : t1/2 = 75.3 s
<h3>Further explanation</h3>
Given
Reaction 45% complete in 65 s
Required
The rate constant and the half life
Solution
For first order ln[A]=−kt+ln[A]o
45% complete, 55% remains
A = 0.55
Ao = 1
Input the value :
ln A = -kt + ln Ao
ln 0.55 = -k.65 + ln 1
-0.598=-k.65
k = 9.2 x 10⁻³ s⁻¹
The half life :
t1/2 = (ln 2) / k
t1/2 = 0.693 : 9.2 x 10⁻³
t1/2 = 75.3 s
<span>1) Humans have how many sets of teeth?
C) 4
2) Adults have how may permanent teeth?
B) 32
3) What type of food products make teeth stronger?
Cheese and Yogurt
4) What is the visible part of the tooth?
C) crown
5) What part of the tooth is harder than bone?
D) dentin
6) What part of the tooth is soft and contains the nerves?
A) pulp
7) What refers to the alignment of the teeth?
</span><span>
Occlusion</span><span>
8) The lower teeth protect what?
D) tongue
9) Malocclusion is the least common reason for referral to orthodontists.
False
10) Usually, malocclusion is hereditary.
True
11) Which type of malocclusion is commonly referred to as an overbite?
Class Two
12) Bacteria are living organisms than cause cavities.
True
13) What is the whitish film that grows on your teeth called?
Plaque
14) What is the best fighter of cavities?
Fluoride
Gingivitis is the inflammation of the
A) gums
16) Gingivitis is permanent.
False
17) Name 2 ways to fight gingivitis.
Proper Toothbrushing and Flossing
</span>Professional Dental Cleanings<span>
18) The cause of gum disease is
B) bacteria
19) Untreated, periodontitis will progress until your teeth loosen and fall out.
True
</span>
Answer:
8 m
Explanation:
3.0 x 10*8 divided by 3.75 x 10*7 = 8 m
Answer:
C.) 2
Explanation:
The pH equation is:
pH = -log[H⁺]
In this equation, [H⁺] is the molarity of the acid. In this case, the acid is HCl. Molarity can be found using the equation:
Molarity (M) = moles / volume (L)
Since you were given moles and volume, you can find the molarity of HCl.
Molarity = moles / volume
Molarity = 0.01 moles / 1.00 L
Molarity = 0.01 M
Now, you can plug the molarity of the acid into the pH equation.
pH = -log[H⁺]
pH = -log[0.01]
pH = 2
