How many protons does nitrogen have? (periodic tablebox

Describe two examples of something that has potential energy to do something

blsea [12.9K]

Answer: the heavy ball of a demolition machine is storing energy when it is held at an elevated position.

Which has potential energy

Explanation:

5 0

3 years ago

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Chromic acid (H2CrO4) is an acid that is used in ceramic glazes and colored glass. The pH of a 0.078 M solution of chromic acid

cestrela7 [59]

Answer:

Ka = 0.1815

Explanation:

Chromic acid

pH = ?

Concentration = 0.078 M

Ka = ?

HCl

conc. = 0.059M

pH = -log(H+)

pH = -log(0.059) = 1.23

pH of chromic acid = 1.23

Step 1 - Set up Initial, Change, Equilibrium table;

H2CrO4 ⇄ H+ + HCrO4−

Initial - 0.078M 0 0

Change : -x +x +x

Equilibrium : 0.078-x x x

Step 2- Write Ka as Ratio of Conjugate Base to Acid

The dissociation constant Ka is [H+] [HCrO4−] / [H2CrO4].

Step 3 - Plug in Values from the Table

Ka = x * x / 0.078-x

Step 4 - Note that x is Related to pH and Calculate Ka

[H+] = 10^-pH.

Since x = [H+] and you know the pH of the solution,

you can write x = 10^-1.23.

It is now possible to find a numerical value for Ka.

Ka = (10^-1.23))^2 / (0.078 - 10^-1.23) = 0.00347 / 0.0191156

Ka = 0.1815

4 0

3 years ago

Explain why metals are good conductors of electric current.

Phantasy [73]

For example, copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity.

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3 years ago

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How much heat is released when 27.6 g P C l subscript 3 cools from 83.1 °C to 55.6 °C? (The specific heat of P C l subscript 3 i

Paul [167]

Answer: Thus 663 J of heat is released when 27.6 g $PCl_3$ cools from 83.1 °C to 55.6 °C

Explanation:

The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

$Q=m\times c\times \Delta T$

Q = Heat released = ?

m = mass of substance = 27.6 g

C = specific heat capacity = $0.874J/g^0C$

Initial temperature= $T_i$ = $83.1^0C$

Final temperature = $T_f$ = $55.6^0c$

Change in temperature , $\Delta T=T_f-T_i=(55.6-83.1)^0C=-27.5^0C$

Putting in the values, we get:

$Q=27.6g\times 0.874J/g^0C\times -27.5^0C=-663J$

As the value of q is negative, it means the heat has been released and it is 663J

7 0

3 years ago

If a 4L solution is 80% concentrated lime juice and 20% water, how much 30% concentrated lime juice must be added so that the co

miv72 [106K]

The volume of 30% concentrated lime juice that must be added to a 4L solution of 80% concentrated lime juice and 20% water is 6 L.

<h3>What are mixtures?</h3>

Mixtures are substances which are formed when two or more substances are physically combined together.

Mixtures are heterogenous in nature and the constituents can be easily separated.

The volume of 30% concentrated lime juice that must be added to a 4L solution of 80% concentrated lime juice and 20% water, so that the concentration of the resulting solution is 50% concentrated lime juice is determined as follows:

Let the volume of 30% lime juice required be x;

total volume of lime juice = 0.3x

For 80% lime juice, volume of lime juice = 0.8 * 4 = 3.2 L

New volume of lime juice = 4 + x

New amount of lime juice added = 3.2 + 0.3x

Also, new amount of lime juice = 0.5 * ( 4 + x)

3.2 + 0.3x = 0.5 * ( 4 + x)

0.2x = 1.2

x = 6 L

In conclusion, the volume to be added is obtained from the percent concentration.

Learn more about percent concentration at: brainly.com/question/19379932

#SPJ1

7 0

2 years ago