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3 years ago

What is the approximate energy of a photon having a frequency of 4 x 10^14 Hz? (h = 6.6 x 10^-34 Js)

Chemistry

1 answer:

Nuetrik [128]3 years ago

7 0

Answer:

option c

Explanation:

E = hf

E= energy

h = Planck constant

f = frequency

E = 6.6 X 10^-34 X 4 X 10^14

E = 2.64 X 10^-19J

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Mg (s) + 2 HCl (aq) --> MgCl2 (aq) + H2 (g)

MrMuchimi

Answer:

2Mg + 4HCl (aq) --> 2 MgCl2 (aq) + H2

Explanation:

balanced...

4 0

3 years ago

25 grams of radon-222 remains after 15.28 days. How much radon was in the original sample? Write an equation for the decay of ra

Crazy boy [7]

Answer:

half-life = 3.8 days

total time of decay = 15.2 days

initial amount = 100. g

number of half-lives past: 15.2/3.8 = 4 half-lives

4 half-lives = 1/16 remains

100. g x 1/16 = 6.25 g

8 0

3 years ago

30.0 ml of an hf solution were titrated with 22.15 ml of a 0.122 m koh solution to reach the equivalence point. what is the mola

a_sh-v [17]

Answer is: molarity of hydrofluoric solution is 0.09 M.

Chemical reaction: HF(aq) + KOH(aq) → KF(aq) + H₂O(l).
V(HF) = 30.0 mL.
c(KOH) = 0.122 M.
V(KOH) = 22.15 mL:
c(HF) = ?.
From chemical reaction: n(HF) : n(KOH) = 1 : 1.
n(HF) = n(KOH).
c(HF) · V(HF) = c(KOH) · V(KOH).
c(HF) = c(KOH) · V(KOH) ÷ V(HF).
c(HF) = 0.122 M · 22.15 mL ÷ 30 mL:
c(HF) = 0.09 M.

8 0

3 years ago

Read 2 more answers

A chemist has 3.55x1022 molecules of nitrogen monoxide. How

Alina [70]

Answer:

<h2>0.059 moles</h2>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

$n = \frac{3.55 \times {10}^{22} }{6.02 \times {10}^{23} } \\ = 0.05897...$

We have the final answer as

<h3>0.059 moles</h3>

Hope this helps you

6 0

3 years ago

How many milliliters of 0. 0140 m na2s2o3 solution are needed to dissolve 0. 590 g of agbr? agbr(s) 2na2s2o3(aq)→na3ag(s2o3)2(aq

Marina86 [1]

The molarity of the solution can be used to give the moles and the volume of the solution. The 0.0140 M sodium thiosulfate needs 225 ml of volume.

<h3>What is molarity?</h3>

Molarity is the property of the solution that is given by the ratio of the moles of the solute to the volume of the solution in liters.

Given,

Molarity of Sodium thiosulfate = 0.0140 M

Mass of solute (AgBr) = 0.590 gm

Molar mass of AgBr = 187.77 g/mol

First moles from the mass can be calculated as,

Moles = mass ÷ molar mass

n = 0.590 g ÷ 187.77 g/mol

= 0.00314 moles

Now, the volume of the solution from molarity is calculated as,

Volume = moles ÷ molarity

= 0.00314 moles ÷ 0.0140

= 0.225 L

Therefore, 225 mL is the volume required.

Learn more about molarity here:

brainly.com/question/13889022

#SPJ4

3 0

2 years ago