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2 years ago

HELP ASAP! I will give brainiest if you answer all questions correctly.

Chemistry

2 answers:

oksano4ka [1.4K]2 years ago

4 0

Answer:

28) -88kj

29) 300kj

30) -204kj

DaniilM [7]2 years ago

4 0

Answer:

28). 261

29). 788

30).-6201

Explanation:

I just took lesson and it said those were correct, I added screenshots of the lesson if you need it :)

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A chemical compound mixture of carbon and one or more elements from the halogen series of elements is known as ____.

Ilya [14]

The correct answer is a salt.

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2 years ago

Acetone is one of the most important solvents in organic chemistry. It is used to dissolve everything from fats and waxes to air

Yanka [14]

Answer: a. 79.6 s

b. 44.3 s

c. 191 s

Explanation:

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$t_{\frac{1}{2}}=\frac{0.693}{8.7\times 10^{-3}s^{-1}}=79.6s$

b) for completion of 32% of reaction

$t=\frac{2.303}{k}\log\frac{100}{100-32}$

$t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{68}$

$t=44.3s$

c) for completion of 81 % of reaction

$t=\frac{2.303}{k}\log\frac{100}{100-81}$

$t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{19}$

$t=191s$

4 0

1 year ago

Compound A is an organic compound which contains Carbon, Hydrogen and Oxygen. When 0.240g of the vapour of A is slowly passed ov

vesna_86 [32]

(a) In this section, give your answers to three decimal places.

(i)

Calculate the mass of carbon present in 0.352 g of CO

Use this value to calculate the amount, in moles, of carbon atoms present in 0.240 g

(ii)

Calculate the mass of hydrogen present in 0.144 g of H

Use this value to calculate the amount, in moles, of hydrogen atoms present in 0.240 g

(iii)

Use your answers to calculate the mass of oxygen present in 0.240 g of

Use this value to calculate the amount, in moles, of oxygen atoms present in 0.240 g

(b)

Use your answers to

(a)

to calculate the empirical formula of

thank you

hope it helpsss

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2 years ago

A roll of tape measures 45.5 inches. What is the length of the tape in meters?

FinnZ [79.3K]

1.5 metres is the length of the tape. Hope this helps :)

8 0

1 year ago

Green light has a frequency of about 6.00×1014s−1. What is the energy of a photon of green light?

Sindrei [870]

3.98 x 10⁻¹⁹ Joule

<h3>Further explanation</h3>

<u>Given:</u>

The green light has a frequency of about 6.00 x 10¹⁴ s⁻¹.

<u>Question:</u>

The energy of a photon of green light (in joules).

<u>The Process:</u>

The energy of a photon is given by $\boxed{\boxed{ \ E = hf \ }}$

E = energy in joules
h = Planck's constant 6.63 x 10⁻³⁴ Js
f = frequency of light in Hz (sometimes the symbol f is written as v)

Let us find out the energy of the green light emitted per photon.

$\boxed{ \ E = (6.63 \times 10^{-34})(6.00 \times 10^{14}) \ }$

Thus, we get a result of $\boxed{\boxed{ \ E = 3.98 \times 10^{-19} \ J \ }}$

- - - - - - - - - -

Notes

When an electron moves between energy levels it must emit or absorb energy.
The energy emitted or absorbed corresponds to the difference between the two allowed energy states, i.e., as packets of light called photons.
A higher energy photon corresponds to a higher frequency (shorter wavelength) of light.

<h3>Learn more</h3>

The energy of the orange light emitted per photon brainly.com/question/2485282#
Determine the density of our sun at the end of its lifetime brainly.com/question/5189537
Find out the kinetic energy of the emitted electrons when metal is exposed to UV rays brainly.com/question/5416146

Keywords: green light, frequency, the energy, a photon, Planck's constant, electrons, emitted, wavelength, joules

7 0

2 years ago