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2 years ago

Which of the following is an example of a combustion reaction ?

Chemistry

1 answer:

Strike441 [17]2 years ago

7 0

Answer:

D. release of carbon dioxide on heating limestone

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You use a _______ when you are changing compounds

zvonat [6]

Answer:

snetence

Explanation:

nikkak youk dxmbk aslk istgk

3 0

2 years ago

. A bright violet line occurs at 435.8 nm in the emission spectrum of mercury vapor. What amount of energy, in joules, must be r

Tom [10]

Answer : The energy released by an electron in a mercury atom to produce a photon of this light must be, $4.56\times 10^{-19}J$

Explanation : Given,

Wavelength = $435.8nm=435.8\times 10^{-9}m$

conversion used : $1nm=10^{-9}m$

Formula used :

$E=h\times \nu$

As, $\nu=\frac{c}{\lambda}$

So, $E=h\times \frac{c}{\lambda}$

where,

$\nu$ = frequency

h = Planck's constant = $6.626\times 10^{-34}Js$

$\lambda$ = wavelength = $435.8\times 10^{-9}m$

c = speed of light = $3\times 10^8m/s$

Now put all the given values in the above formula, we get:

$E=(6.626\times 10^{-34}Js)\times \frac{(3\times 10^{8}m/s)}{(435.8\times 10^{-9}m)}$

$E=4.56\times 10^{-19}J$

Therefore, the energy released by an electron in a mercury atom to produce a photon of this light must be, $4.56\times 10^{-19}J$

3 0

3 years ago

What is the mass of 2.23 × 10^23 atoms of aluminum?

rjkz [21]

Answer:

Explanation:

In image

Take atomic mass or molar mass

of Al =27

7 0

2 years ago

Write the chemical formula for the cation present in the aqueous solution of cuso4.

Inessa05 [86]

The ionic compounds on dissolving in aqueous solution dissociate into their respective ions that are cations and anions.

The ions present in the aqueous solution of $CuSO_4$ are $Cu^{2+}$ and $SO_{4}^{2-}$ .

So, the chemical formula of the cation present in the aqueous solution of $CuSO_4$ is $Cu^{2+}$ .

4 0

2 years ago

Which of the following is not a conjugate acid-base pair?

-Dominant- [34]

Answer:

A. H3O+/OH−

Explanation:

A conjugate acid-base pair are a pair of molecules that differ in 1 H⁺

A. The conjugate pair of H₃O⁺ = H₂O not OH⁻

B. The conjugate pair of NH₄⁺ is NH₃

C. The conjugate pair of C₂H₃O₂⁻ is HC₂H₃O₂

D. The conjugate pair of H₂SO₃ is HSO₃⁻

That means right option, that is not a conjugate acid-base pair, is:

5 0

3 years ago