The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
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NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
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KOH
- it is a strong base (pH=14)
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He needs to use HF (Hydrogen fluoride) to decrease the pH.
Answer:
The velocity of the man is 0.144 m/s
Explanation:
This is a case of conservation of momentum.
The momentum of the moving ball before it was caught must equal the momentum of the man and the ball after he catches the ball.
Mass of ball = 0.65 kg
Mass of the man = 54 kg
Velocity of the ball = 12.1 m/s
Before collision, momentum of the ball = mass x velocity
= 0.65 x 12.1 = 7.865 kg-m/s
After collision the momentum of the man and ball system is
(0.65 + 54)Vf = 54.65Vf
Where Vf is their final common velocity.
Equating the initial and final momentum,
7.865 = 54.65Vf
Vf = 7.865/54.65 = 0.144 m/s
Answer: the ball will have a charge of 8x10^8C when we remove 5x10^27 electrons.
Explanation:
If the sphere is neutral, then the charge of the sphere is 0C
Now, when we remove an electron (-1.6*10^-19 C) we are subtracting a negative number, so the new charge of the sphere is: 1.6*10^-19 C
Now, for N removed electrons, the charge of the sphere is:
N*1.6*10^-19 C
We want to find the number N when:
N*1.6*10^-19 C = 8.0x 10^8 C
N = (8.0/1.6)x10^(8 + 19) = 5x10^27 electrons.
Answer:
Our solar system has total eight planets out of which four are inner planets and four are outer planets. The four outer planets are Jupiter, Saturn, Uranus and Neptune. The common characteristics of outer planets is that they are gaseous planets. They are larger on size than the inner rocky planets and are faraway from Sun. They have larger period of revolution around the Sun.
Uranus is a gaseous planet and lies far from Sun and hence has large period of revolution. It takes 84 Earth years to revolve around Sun. This data indicates that Uranus resides in the outer region of the Solar System.