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2 years ago

How to describe a ufo??

Chemistry

2 answers:

erastova [34]2 years ago

6 0

Answer:

Unidentified flying object or fly saucer.

Explanation:

Likurg_2 [28]2 years ago

3 0

Answer:

It is a silver dish that has round windows around it with little circluar lights round it too.

You might be interested in

What is the form of energy present in the pizza that we eat? group of answer choices mechanical chemical potential radiation.

PIT_PIT [208]

Answer:

Chemical energy

Explanation:

When the body eats food our bodies convert the stored energy (calories) to chemical energy, allowing us to function.

8 0

2 years ago

What is the pH of a solution prepared by mixing 100.00 mL of 0.020 M Ca(OH)2 with 50.00 mL of 0.100 M NaOH? Assume that the volu

klemol [59]

Answer:

The pH of the solution is 12.78.

Explanation:

The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution. The pOH is defined as the negative logarithm of the activity of the hydroxide ions. That is, the concentration of OH- ions:

pOH= - log [OH-]

On the other side, Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume. Molarity is calculated as:

$Molarity= \frac{number of moles}{volume}$

Molarity is expressed in units: $\frac{moles}{liter}$

In this case, the solution is prepared by mixing 100 ml (equal to 0.1 L, where 1000 mL = 1 L) of Ca(OH)₂ 0.020 M with 50 ml (equal to 0.05 L) of 0.100 M NaOH. Then, Ca(OH)₂ and NaOH are strong bases, so they dissociate completely. In the case of the first hydroxide, for each mole of Ca(OH)₂,

form two moles of OH-. In the case of sodium hydroxide, for each mole of hydroxide, one mole of OH- is formed. So, taking into account the definition of molarity, the number of moles of OH- that each hydroxide contributes to the solution is calculated as:

From Ca(OH)₂: 0.1 L* 0.02 M*2 = 0.004 moles

From NaOH: 0.05 L* 0.1 M= 0.005 moles

So, the amount of total moles of OH- is the sum that each hydroxide contributes to the solution: 0.004 moles + 0.005 moles= 0.009 moles

On the other hand, volumes are additive. Then: 0.1 L + 0.05 L= 0.15 L

Replacing in the definition of molarity the number of moles and the volume:

$[OH-]=\frac{0.009 moles}{0.15 L}$

Solving:

[OH-]= 0.06 $\frac{moles}{liter}$

Replacing in the definition of pOH:

pOH= - log 0.06

pOH= 1.22

The following relationship can be established between pH and pOH:

pH + pOH= 14

Being pOH= 1.22 and replacing:

pH + 1.22= 14

pH= 14 - 1.22

pH= 12.78

The pH of the solution is 12.78.

7 0

3 years ago

When carbon is oxidized in a small amount of oxygen, the principle product formed is carbon monoxide (co). when the oxidation oc

skad [1K]

It generally does not mean that there is double the oxygen, but in this case there is double, because the subscript number tells how many atoms of that element are in a particle. In this case, there are two of the oxygen, hence the DI-oxide verbiage, and one of the carbon. When there is only one, it's MONOxide, to indicate only one atom.

6 0

3 years ago

Give the mathematical relationship for an unsaturated solution in comparing Q with K sp:__________.

e-lub [12.9K]

Answer:

Q < Ksp

Explanation:

The general equilibrium of a constant product solubility, ksp, is:

AB ⇄ A⁺ + B⁻

Where Ksp is defined as:

Ksp = [A⁺] [B⁻]

When [A⁺] [B⁻] = Ksp, the solution is saturated or oversaturated because there are the maximum amount of ions that solution can dissolve.

When the solution is oversaturated, AB is produced.

Now, in a unsaturated solution, the [A⁺] [B⁻] is less than the maximum amount that can be dissolved. That means:

[A⁺] [B⁻] = Q < Ksp

Q is defined in the same way than Ksp, just in Q the system is not in equilibrium.

Right answer is:

3 0

3 years ago

How many kilojoules of energy would be required to heat a 225g block of aluminum from 23.0 C to 73.5 C?

gulaghasi [49]

Answer:

$\boxed {\boxed {\sf 10.2 \ kJ}}$

Explanation:

We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.

We will use the following formula to calculate heat energy.

$q=mc \Delta T$

The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.

ΔT = final temperature - inital temperature

The aluminum block was heated from 23.0 °C to 73.5 °C.

ΔT= 73.5 °C - 23.0 °C = 50.5 °C

Now we know all three variables and can substitute them into the formula.

m= 225 g
c= 0.897 J/g° C
ΔT= 50.5 °C

$q= (225 \ g )(0.897 \ J/g \textdegree C)(50.5 \textdegree C)$

Multiply the first two numbers. The units of grams cancel.

$q= (225 \ g * 0.897 \ J/g \textdegree C)(50.5 \textdegree C)$

$q= (225 * 0.897 \ J / \textdegree C)(50.5 \textdegree C)$

$q= (201.825\ J / \textdegree C)(50.5 \textdegree C)$

Multiply again. This time, the units of degrees Celsius cancel.

$q= 201.825 \ J * 50.5$

$q= 10192.1625 \ J$

The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.

$\frac { 1 \ kJ}{ 1000 \ J}$

Multiply by the answer we found in Joules.

$10192.1625 \ J * \frac{ 1 \ kJ}{ 1000 \ J}$

$10192.1625 * \frac{ 1 \ kJ}{ 1000 }$

$\frac {10192. 1625}{1000} \ kJ$

$10.1921625 \ kJ$

The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.

$10.2 \ kJ$

Approximately 10.2 kilojoules of energy would be required.

3 0

3 years ago

How to describe a ufo??​

How to describe a ufo??