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3 years ago

14

In the early studies of chemistry, scientists used properties and changed to help identify compounds. this is still done today.

if you were given the following observation about salt water, how would you classify it? "when electricity flows through a flask of salt water, bubbles form in the water. these bubbles, when collected, will burn."

1 answer:

aalyn [17]3 years ago

4 0

Answer:

as an inflammable substance

Explanation:

Because when it reacts with electricity and water start to produce bubbles, and these bubbles burn, that mean is a substance flammable.

Now a days it is needed to have more test to identify a substance and to classify not just by the physical properties, also by the chemical properties and even more, by the chemical behavior in front of other substances.

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PLEASE HELP ME ON THIS

lisabon 2012 [21]

Answer:

The conductance will increase as the concentration of the electrolyte is increased.

Explanation:

The ions are what carry the charges from one electrode to another. The more there are, the easier it is for electrons to get across the solution of electrolyte,

3 0

2 years ago

Given the balanced equation representing a reaction:

Vilka [71]

(2) a base because they accept H+ ions. NH3 is the conjugate base of NH4+.

5 0

3 years ago

What is the mole fraction of NaOH in an aqueous solution that

astraxan [27]

Answer:

The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882

Explanation:

We are given that

Aqueous solution that contains 22.9% NaOH by mass means

22.9 g NaOH in 100 g solution.

Mass of NaOH(WB)=22.9 g

Mass of water =100-22.9=77.1

Na=23

O=16

H=1.01

Molar mass of NaOH(MB)=23+16+1.01=40.01

Number of moles = $\frac{Given\;mass}{Molar\;mass}$

Using the formula

Number of moles of NaOH $(n_B)=\frac{W_B}{M_B}=\frac{22.9}{40.01}$

$n_B=0.572moles$

Molar mass of water=16+2(1.01)=18.02g

Number of moles of water $(n_A)=\frac{77.1}{18.02}$

$n_A=4.279 moles$

Now, mole fraction of NaOH

= $\frac{n_B}{n_B+n_A}$

$=\frac{4.279}{0.572+4.279}$

=0.882

Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882

4 0

3 years ago

The hydrogen chloride (HCl) molecule has an internuclear separation of 127 pm (picometers). Assume the atomic isotopes that make

natta225 [31]

Answer:

the energy of the third excited rotational state $\mathbf{E_3 = 16.041 \ meV}$

Explanation:

Given that :

hydrogen chloride (HCl) molecule has an intermolecular separation of 127 pm

Assume the atomic isotopes that make up the molecule are hydrogen-1 (protium) and chlorine-35.

Thus; the reduced mass μ = $\dfrac{m_1 \times m_2}{m_1 + m_2}$

μ = $\dfrac{1 \times 35}{1 + 35}$

μ = $\dfrac{35}{36}$

∵ 1 μ = 1.66 × 10⁻²⁷ kg

μ = $\\ \\ \dfrac{35}{36} \times 1.66 \times 10^{-27} \ \ kg$

μ = 1.6139 × 10⁻²⁷ kg

$r_o = 127 \ pm = 127*10^{-12} \ m$

The rotational level Energy can be expressed by the equation:

$E_J = \dfrac{h^2}{8 \pi^2 I } \times J ( J +1)$

where ;

J = 3 ( i.e third excited state) &

$I = \mu r^2_o$

$E_J= \dfrac{h^2}{8 \pi \mu r^ 2 \mur_o } \times J ( J +1)$

$E_3 = \dfrac{(6.63 \times 10^{-34})^2}{8 \times \pi ^2 \times 1.6139 \times 10^{-27} \times( 127 \times 10^{-12}) ^ 2 } \times 3 ( 3 +1)$

$E_3= 2.5665 \times 10^{-21} \ J$

We know that :

1 J = $\dfrac{1}{1.6 \times 10^{-19}}eV$

$E_3= \dfrac{2.5665 \times 10^{-21} }{1.6 \times 10^{-19}}eV$

$E_3 = 16.041 \times 10 ^{-3} \ eV$

$\mathbf{E_3 = 16.041 \ meV}$

8 0

2 years ago

What is the frequency of 3.98 x 10^-77

LekaFEV [45]

Answer:

What is the frequency of a 6.9 x 10-13 m wave? 3.00 x 108 = 6.9x10-13 mly). GAMMA. V = 4.35 x 10 20 5-11. 3. What is the wavelength of a 2.99 Hz wave?

Missing: 3.98 ‎77

Explanation:

5 0

3 years ago