When a system performs work on the surroundings, the work is reported with a negative sign. True of False
Answers
The statement that is given above “When a system performs work on the surroundings, the work is reported with a negative sign” is true. When the surrounding performs work by the system, it is positive.
Related Questions
Describe how chemistry is a part of your morning routine?
The atomic weight of an unknown element, in atomic units (amu), is approximately 20% less than that of calcium, the atomic weight of calcium is 40 amu. Which of the following best approximates the atomic weight, in amu, of the unknown element? (a) 8 (b) 20 (c) 32 (d) 48
Use electron transfer or electron shift to identify what is oxidized and what is reduced in each reaction :a) 2Na(s) + Br2(l) ----> 2NaBr(s) b) H2(g) + Cl2(g) ----> 2HCl(g) c) 2Li(s) + F2(g) ----> 2LiF(s) d) S(s) + Cl2(g) ----> SCl2(g) e)N2(g) + 2O2(g) ----> 2NO2(g) f) Mg(s) +Cu(NO3)2(aq) = Mg(NO3)2(aq) + Cu(s) For each reaction above, identify the reducing agent and the oxidizing agent
During an experiment, a student observes the formation of a precipitate. Why does this indicate that a chemical reaction is likely occurring? 1)A solid forms, and there is a change of color. 2)A gas forms, and there is a change of color. 3)A solid forms, and light is emitted. 4)A gas forms, and light is emitted.
B. an increase in atomic radius and an increase in electronegativity.
C. a decrease in atomic radius and a decrease in electronegativity.
D. an increase in atomic radius and a decrease in electronegativity.
E. None of these answer choices is correct.
Answers
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Therefore, the correct option is option A.
What is periodic table?
Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Within a period, an increase in atomic number is usually accompanied by a decrease in atomic radius and an increase in electronegativity.
Therefore, the correct option is option A that is a decrease in atomic radius and an increase in electronegativity.
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(1) HCl (3) NH3
(2) H2O (4) CH4
Answers
Answer:
(4) CH4
Explanation:
When there are no polar bonds in a molecule, there is no permanent charge difference between one part of the molecule and another, and the molecule is nonpolar.
In option A, HCl is not nonpolar because Cl has a pretty high electronegativity of 3.16, the H-Cl bond is polar due to the electronegative difference. This means option A is wrong.
In option B, A water molecule is polar because (1) its O-H bonds are significantly polar, and (2) its bent geometry makes the distribution of those polar bonds asymmetrical. The side of the water molecule containing the more electronegative oxygen atom is partially negative, and the side of the molecule containing the less electronegative hydrogen atoms is partially positive.
In option C, NH3 is polar because it has 3 dipoles that do not cancel out. Each N-H bond is polar because N is more electronegative than H. NH3 is overall asymmetrical in its VSEPR shape, so the dipoles don't cancel out and it is therefore polar.
In option D, CH4 looks like a C in the middle with 4 H's coming off of it. It is nonpolar because the electronegative difference is balanced. The H's all have the same electronegativities, and all cancel out since they are opposite one another.
This is because CH4 is both symmetrical in its molecular format and also does not have any lone pairs.
Because of that, the charges on it are balanced, and if all charges are balanced, it means that the molecule is non-polar
Answer: (4) CH4
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Given that the molar mass of CO2 is 44.01 g/mol, how many liters of oxygen is required at STP to produce 88.0 g of CO2 from this reaction?
44.8 L
45.00 L
89.55 L
89.6 L
Answers
Answer:
89.6 L of O₂
Solution:
The balanced chemical equation is as,
CH₄ + 2 O₂ → CO₂ + 2 H₂O
As at STP, one mole of any gas (Ideal gas) occupies exactly 22.4 L of Volume. Therefore, According to equation,
44 g ( 1 mol) CO₂ is produced by = 44.8 L (2 mol) of O₂
So,
88 g CO₂ will be produced by = X L of O₂
Solving for X,
X = (88 g × 44.8 L) ÷ 44 g
X = 89.6 L of O₂
D) 89.6 L
CH3CH(CH3)CH2CH(CH3)2
Answers
The name of the given Alkane molecule is 2,4-di-methyl Pentane. It can be named with the help of IUPAC Nomenclature technique.
What is IUPAC Nomenclature ?
IUPAC is an acronym for International Union of Pure and Applied Chemistry, which is a globally recognize international chemistry standards organization that has named all the chemical organic substances in a systematic manner
All deviations, either multiple bonds or atoms other than carbon and hydrogen, are indicated by prefixes or suffixes according to a specific set of priorities.
Therefore, The name of the given Alkane molecule is 2,4-di-methyl Pentane. It can be named with the help of IUPAC Nomenclature technique.
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Answer:
answer is C
Explanation:
Answers
Answer: There are 2 oxygen atoms on the reactant side.
Explanation:
Every balanced chemical equation follows law of conservation of mass.
This law states that mass can neither be created nor be destroyed, but it can only be transformed from one form to another form.
This law also means that total number of individual atoms on the reactant side will always be equal to the total number of individual atoms on the product side.
The given balanced chemical equation follows:
On reactant side:
Number of hydrogen atoms = 4
Number of oxygen atoms = 2
On product side:
Number of hydrogen atoms = 4
Number of oxygen atoms = 2
Hence, the number of oxygen atoms on the reactant side is equal to 2.
The following balanced equation, 2H2O = 2H2 +O2, shows the decomposition of water (H2O). According to the equation, there are two oxygen atoms in the reactants and another two oxygen atoms in the product side.