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3 years ago

I need help ASAP!

1 answer:

8 0

Calcium reacts gently with water to give hydrogen and calcium hydroxide, which is only slightly soluble, thus slows down the reaction.

It will be assumed that hydrochloric acid used is a dilute aqueous solution.

However, calcium reacts with hydrochloric acid to give calcium chloride which is readily soluble in water, and hydrogen, being a typical reaction of relatively active metals with acids.
Ca(s) + 2HCl(aq) -> CaCl2(aq) +H2(g) ↑ + heat

The clues that it is a chemical reaction could be:
- formation of a new substance, gaseous hydrogen
- disappearance of a metallic solid in the solution
- heat formed during the vigorous reaction.

As silver is below hydrogen in the electrochemical series, it will not be expected to react with dilute hydrocloric acid. (however, it dissolves in oxidizing acid such as nitric acid, but not displacing hydrogen as a product).

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2. All metals are good conductors because their electrons can

dsp73

Answer: An insulator would be made out of material unable to conduct electricity due to lack of fluid movement for electrons, such as rubber. Rubber properties not only prevents them from freely moving, but also helps electrons stay tightly bound to each other.

Hope this helps ^_^

4 0

3 years ago

As with other ionic compounds, potassium bromate, KBrO3, dissociates into ions when it dissolves in water. If 13.8 g of KBrO3 is

chubhunter [2.5K]

Answer:

ΔH of dissociation is 38,0 kJ/mol

Explanation:

The dissociation reaction of KBrO₃ is:

<em>KBrO₃ → K⁺ + BrO₃⁻ </em>

This dissolution consume heat that is evidenced with the decrease in water temperature.

The heat consumed is:

q = CΔTm

Where C is specific heat of water (4,186 J/mol°C)

ΔT is the temperature changing (18,0°C - 13,0°C = 5,0°C)

And m is mass of water (150,0 mL ≈ 150,0 g)

Replacing, heat consumed is:

q = 3139,5 J ≡ 3,14 kJ

13,8 g of KBrO₃ are:

13,8 g×(1mol/167g) = 0,0826 moles

Thus, ΔH of dissociation is:

3,14kJ / 0,0826mol = <em>38,0 kJ/mol</em>

I hope it helps!

3 0

3 years ago

If you mix cu2+ with? a. nacl, b. nano2, c. h2o , arrange the solutions based on their absorption from highest frequency to lowe

erica [24]

The arrangement of the solutions based on their absorption from highest frequency to lowest frequency :

b. $NaN$ $O_{2}$ > c. $H_{2} O$ > a.NaCl

<h3>What is absorption frequency?</h3>

The frequency of the molecular vibration that led to the absorption is the same as the absorption frequency of a basic IR absorption band.

In a way, an emission spectrum is the opposite of an absorption spectrum.
The discrepancies in the energy levels of each chemical element's orbitals correspond to absorption lines for each chemical element at various particular wavelengths.
Therefore, it is possible to identify the constituents in a gas or liquid using its absorption spectrum.
Absorption spectroscopy is most frequently used to measure infrared, atomic, visible, ultraviolet (UV), and x-ray waves.

Learn more about Absorption frequency here:

brainly.com/question/5032775

#SPJ4

3 0

1 year ago

The modern periodic table is arranged in order of increasing. true or false

qaws [65]

Answer:

Increasing atomic number - True

Explanation:

The modern table is based on Mendeleev’s table, except the modern table arranges the elements by increasing atomic number instead of atomic mass.

The Atomic number is the number of protons in an atom, and this number is unique for each element. For example, Hydrogen has an atomic number of 1, Calcium has an atomic number of 20.

In the modern periodic table the elements are further arranged into:

- rows, called periods, in order of increasing atomic number. Elements in the same periods have the same number of shells.

- vertical columns, called groups, where the elements have similar properties. Elements in the same group has the same number of valency (outermost number of electrons)

4 0

3 years ago

Jonathan used the following soil triangle to identify a sample of soil as sandy clay. Which description of soil likely allowed J

Papessa [141]

Answer:

Mostly large grains, with a sticky texture, 55% sand, 40% clay, and 5% silt

Explanation: I took the test, hope it helps.

7 0

3 years ago