Answer: I disagree. Elements form all pure substances, but some pure substances include elements bonded together to form molecules and compounds.
Explanation:
Pure substances are those that have a uniform and constant (invariable) composition.
That condition is met by both elements and compounds.
Elements are pure substances of one only kind of atoms. For example, gold, oxygen, sodium, hydrogen, are pure substances that arer elements. There are 118 elements known and they are all listed in the periodic table.
Compounds are pure substances formed by two or more different kind of atoms. Water (H₂O), table salt (NaCl), and ethanol (CH₃-CH₂OH), are examples of pure substances that are compounds. There are pratically infinite different compounds.
In conclusion, compounds are also pure substances, since every sample of a given compound has always the same kind of elements bonded in the same way.
Answer:
3.762 atm.
Explanation:
- We can use the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
- If n and T are constant, and have different values of P and V:
<em>(P₁V₁) = (P₂V₂)</em>
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P₁ = 894.0 torr, V₁ = 534.0 mL,
P₂ = ??? torr, V₂ = 167.0 mL.
- Applying in the above equation
(P₁V₁) = (P₂V₂)
<em>∴ P₂ = (P₁V₁)/V₂</em> = (894.0 torr)(534.0 mL)/(167.0 mL) = <em>2859 torr.</em>
- To convert from torr to atm:
1.0 atm = 760.0 torr.
<em>∴ P₂ </em>= (2859 torr)(1.0 atm/760 torr) = <em>3.762 atm.</em>
Answer:
319.8 m/min
Explanation:
533 cm/s
We can convert 533 cm/s to m/min by doing the following:
First, we shall convert 533 cm/s to m/s. This can be obtained as illustrated below:
Recall:
100 cm/s = 1 m/s
Therefore,
533 cm/s = 533 cm/s /100 cm/s × 1 m/s
533 cm/s = 5.33 m/s
Finally, we shall convert 5.33 m/s to m/min. This can be obtained as follow:
1 m/s = 60 m/min
Therefore,
5.33 m/s = 5.33 m/s / 1 m/s × 60 m/min
5.33 m/s = 319.8 m/min
Therefore, 533 cm/s is equivalent to 319.8 m/min
The octet rule is that atoms must have 8 valence electrons to have an octet. Usually, when atoms have an octet, they tend not to bond with any other atoms because they are already stable and do not need to bond anymore.
= 3.6 mol H₂