Answer: 9.91×10²³ particles
Explanation:
To find the amount of particles, you will need to use the Ideal Gas Law with what we are given.
Ideal Gas Law: PV=nRT
After we find moles, we can use Avogadro's number to convert to particles.
P=101.3kPa=1.00 atm
V=4.0 L
T=23°C+273.15=296.15 K
R=0.08206 Latm/Kmol
Now that we have moles, we can convert to particles.
Answer:
Explanation:
<u>1) Data:</u>
Base: NaOH
Vb = 15.00 ml = 15.00 / 1,000 liter
Mb = ?
Acid: H₂SO₄
Va = 17.88 ml = 17.88 / 1,000 liter
Ma = 0.1053
<u>2) Chemical reaction:</u>
The <em>titration</em> is an acid-base (neutralization) reaction to yield a salt and water:
- Acid + Base → Salt + Water
- H₂SO₄ (aq) + NaOH(aq) → Na₂SO₄ (aq) + H₂O (l)
<u>3) Balanced chemical equation:</u>
- H₂SO₄ (aq) + 2 NaOH(aq) → Na₂SO₄ (aq) + 2H₂O (l)
Placing coefficient 2 in front of NaOH and H₂O balances the equation
<u>4) Stoichiometric mole ratio:</u>
The coefficients of the balanced chemical equation show that 1 mole of H₂SO₄ react with 2 moles of NaOH. Hence, the mole ratio is:
- 1 mole H₂SO₄ : 2 mole NaOH
<u>5) Calculations:</u>
a) Molarity formula: M = n / V (in liter)
⇒ n = M × V
b) Nunber of moles of acid:
- nₐ = Ma × Va = 0.1053 (17.88 / 1,000)
c) Number of moles of base, nb:
- nb = Mb × Vb = Mb × (15.00 / 1,000)
d) At equivalence point number of moles of acid = number of moles of base
- 0.1053 × (17.88 / 1,000) = Mb × (15.00 / 1,000)
- Mb = 0.1053 × 17.88 / 15.00 = 0.1255 mole/liter = 0.1255 M
Answer
2.7956 * 10^19 photons
Givens
- Wavelength = λ = 525 * 10^-9 meters [1 nmeter = 1*10^-9 meters]
- c = 3 * 10^8 meters
- E = ???
- W = 100 watts
- t = 1 second
- h= plank's Constant = 6.26 * 10^-34 J*s
Formula
E = h * c / λ
W = E / t
Solution
E = 6.26 * 10^-34 j*s * 3 * 10^8 m/s /525 * 10^-9 (m)
The meters cancel out. So do the seconds. You are left with Joules as you should be.
E = 3.577 * 10^-18 Joules
What you have found is the energy of 1 photon.
Now you have to find the Joules from the watts.
W = E/t
100 * 1 second = 100 joules
1 photon contains 3.577 * 10 ^ - 18 Joules
x photon = 100 joules
1/x = 3.577 * 10^-18 / 100 Cross multiply
100 = 3.577 * 10 ^ - 18 * x Divide both sides by 3.577 * 10 ^ - 18
100/3.577 * 10 ^ - 18 = 3.577 * 10 ^ - 18x / 3.577 * 10 ^ - 18
2.7956 * 10^19 photons = x
Answer:a weak acid and a weak base
Explanation:
Answer: D. Potassium bromide
