"A machine can decrease either the input force or the input distance needed to do a given amount of work" is the best statement that describes why a machine is useful.
Answer: Option D
<u>Explanation
:</u>
A machine is simply defined as a device that helps humans, helping them to transfer the required amount of force to compete any task, changing the direction of motion, increasing the magnitude of force to complete any task, reduce the time or distance needed to cover while performing any task.
Machines can be simple mechanical device or a combination of multiple mechanical or technical devices to reduce the amount of input force or increase the output.
Answer: Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar.
Explanation:
Polarity is when the electric charge that is leading to a molecule is being separated.
The polarity of SCL4F2 can either be polar or non polar and this depends on the arrangement of outer atoms. It is the arrangements of these outer atoms that'll help in the determination of its polarity.
Answer:
A) Is The Correct Answer
<em><u>PLEASE</u></em><em><u> </u></em><em><u>MARK</u></em><em><u> </u></em><em><u>AS</u></em><em><u> </u></em><em><u>BRAINLIEST</u></em><em><u> </u></em><em><u>ANSWER</u></em><em><u> </u></em>
First, we should get moles acetic acid = molarity * volume
=0.3 M * 0.5 L
= 0.15 mol
then, we should get moles acetate = molarity * volume
= 0.2 M * 0.5L
= 0.1 mol
then, we have to get moles of OH- which added:
moles OH- = molarity * volume
= 1 M * 0.02L
= 0.02 mol
when the reaction equation is:
CH3COOH + OH- → CH3COO- + H2O
moles acetic acid after adding OH- = (0.15-0.02)
= 0.13M
moles acetate after adding OH- = (0.1 + 0.02)
= 0.12 M
Total volume = 0.5 L + 0.02 L= 0.52 L
∴[acetic acid] = moles acetic acid after adding OH- / total volume
= 0.13mol / 0.52L
= 0.25 M
and [acetate ) = 0.12 mol / 0.52L
= 0.23 M
by using H-H equation we can get PH:
PH = Pka + ㏒[salt/acid]
when we have Ka = 1.8 x 10^-5
∴Pka = -㏒Ka
= -㏒ 1.8 x 10^-5
= 4.7
So by substitution:
∴ PH = 4.7 + ㏒[acetate/acetic acid]
= 4.7 + ㏒(0.23/0.25)
= 4.66
Answer is: c. 1.204 × 10²⁴ atoms
of carbon.
n(C) = 2 mol; amount of substance of carbon.
Na = 6.02·10²³ 1/mol; Avogadro constant (the number of constituent particles, in this example atoms, that are contained in the amount of substance given by one mole).
N(C) = n(C) · Na.
N(C) = 2 mol · 6.02·10²³ 1/mol.
N(C) = 12.04·10²³ = 1.204·10²⁴; number of carbon atoms in a sample.
