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2 years ago

Selecting resources with reliable credentials and expertise is?

Chemistry

2 answers:

Zina [86]2 years ago

6 0

Answer: D. Important for any information you look up, on any topic.

Explanation:

The resources can be considered as reliable and credentials when they consists of information which comes from an authentic source. Also the resource which has been verified by many reviewers who exhibit special knowledge and expertise in the related field of the topic can be considered as reliable and credential.

Such a resource can be looked upon for retrieving desired information on any topic.

PtichkaEL [24]2 years ago

5 0

Answer:its D

Explanation:

You might be interested in

How many grams of NaOH are produced from 1.20 x 10^2 of Na2O

oksian1 [2.3K]

Write an balance the equation

Na2O + H2O -> 2 NaOH

Calculate the molecular mass of Na2O and NaOH from the atomic mass from the periodic table.

Na = 23
O=16
H=1

Na2O = 23 * 2 + 16 = 62
NaOH = 23+16+1= 40

For the stoichiometry of the reaction one mole of Na2O = 62g produce two mol of NaOH = 2* 40= 80 g

120 g Na2O x 80g NaOH / 62g Na2O=

154.8 g NaOH

5 0

3 years ago

What does anhydrous mean in your own words?

dalvyx [7]

Answer: no water

Explanation:

4 0

3 years ago

Read 2 more answers

A piece of iron is heated with a torch to a temperature of 603 k.

Mazyrski [523]

This question asks to compare the energy emitted by a piece of iron at T = 603K with the energy emitted by the same piece at T = 298K.

Then you need to use the Stefan–Boltzmann Law

That law states that energy emitted (E) is proportional to fourth power of the to the absolute temperature (T), this is E α T^4 (the sign α is used to express proportionallity.

Then E (603) / E (298) = [603K / 298K]^4 = 16,8

Which meand that the Energy emitted at 603 K is 16,8 times the energy emitted at 298K.

5 0

3 years ago

In a process for producing acetic acid, oxygen gas is bubbled into acetaldehyde, CH3CHO, containing manganese(II) acetate (catal

grigory [225]

Answer: The mass of acetic acid that can be produced is 30.24 grams

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For acetaldehyde:

Given mass of acetaldehyde = 22.2 g

Molar mass of acetaldehyde = 44 g/mol

Putting values in equation 1, we get:

$\text{Moles of acetaldehyde}=\frac{22.2g}{44g/mol}=0.504mol$

For oxygen gas:

Given mass of oxygen gas = 12.6 g

Molar mass of oxygen gas = 32 g/mol

Putting values in equation 1, we get:

$\text{Moles of oxygen gas}=\frac{12.6g}{32g/mol}=0.394mol$

The given chemical equation follows:

$2CH_3CHO(l)+O_2(g)\rightarrow 2CH_3COOH(l)$

By Stoichiometry of the reaction:

2 moles of acetaldehyde reacts with 1 mole of oxygen gas

So, 0.504 moles of acetaldehyde will react with = $\frac{1}{2}\times 0.504=0.252mol$ of oxygen gas

As, given amount of oxygen gas is more than the required amount. So, it is considered as an excess reagent.

Thus, acetaldehyde is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of acetaldehyde produces 2 moles of acetic acid

So, 0.504 moles of acetaldehyde will produce = $\frac{2}{2}\times 0.504=0.504moles$ of acetic acid

Now, calculating the mass of acetic acid from equation 1, we get:

Molar mass of acetic acid = 60 g/mol

Moles of acetic acid = 0.504 moles

Putting values in equation 1, we get:

$0.504mol=\frac{\text{Mass of acetic acid}}{60g/mol}\\\\\text{Mass of acetic acid}=(0.504mol\times 60g/mol)=30.24g$

Hence, the mass of acetic acid that can be produced is 30.24 grams

8 0

3 years ago

A sample of gas has a volume of 2.00 L and a pressure of 0.750 kPa when its

Gennadij [26K]

Answer:

The final temperature is 397 K.

Explanation:

Boyle's law relates volume and pressure by expressing:

"The volume occupied by a certain gaseous mass at constant temperature is inversely proportional to pressure"

Boyle's law is expressed mathematically as:

P * V = k

where k is a constant.

Charles's Law consists of the relationship between the volume and the temperature of a certain amount of ideal gas, which is kept at a constant pressure. This law states: "At constant pressure, the volume that a gas sample occupies is directly proportional to the temperature"

So, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the ratio between the volume and the temperature will always have the same value:

$\frac{V}{T}=k$

Finally, Gay-Lussac's law establishes the relationship between pressure and temperature of a gas when the volume is constant. This law states that the pressure of a fixed volume of a gas is directly proportional to its temperature. That is, if the volume of a certain quantity of ideal gas at moderate pressure is kept constant, the quotient between pressure and temperature remains constant.

$\frac{P}{T}=k$

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law. So, you have:

$\frac{P*V}{T}=k$

Supposing you have a gas that is at a pressure P1, at a volume V1 and at a temperature T1 at the beginning of the experiment, by varying the temperature to a new value T2, then the pressure will change to P2 and the volume to V2, and will fulfill:

$\frac{P1*V1}{T1}=\frac{P2*V2}{T2}$

In this case, you have:

P1= 0.750 kPa
V1= 2 L
T1= 25°C= 298 °K (being 0°C=273°K)
P2= 0.500 kPa
V2= 4 L
T2= ?

Replacing:

$\frac{0.750 kPa* 2 L}{298 K}=\frac{0.500 kPa*4 L}{T2}$

and solving you get:

$T2=\frac{0.500 kPa*4 L}{\frac{0.750 kPa* 2 L}{298 K}}$

T2= 397 K

The final temperature is 397 K.

4 0

2 years ago