Answer: Hund’s rule
Explanation:
You are a chemist working in your laboratory. In your storage closet you have a
cabinet that holds only samples of pure elements, no compounds. While looking for a
sample of lithium (LI), you notice that the label on one bottle has worn off. The room is
at normal temperature. The contents of the bottle are liquid and do not look metallic.
What element should you relabel the bottle as?
A.Helium
B.Bromine
C.Arsenic
D.Chlorine
For a reaction, AH = 176 kJ/mol and A SO = 0.285 kJ/(K•mol). At what
temperatures is this reaction spontaneous?
A. At no temperature
B. T< 50 K
C. T>617 K
D. T< 617 K
Answer:
C. T>617 K
Explanation:
We are given that
[tex]\Delta H=176KJ/mol[/tex]
[tex]\Delta S=0.285KJ/K\cdot mol[/tex]
We have to find the temperature at which the reaction is spontaneous.
When
[tex]\Delta H>0, \Delta S>0[/tex]
Therefore, the reaction is spontaneous at certain range of temperature.
Option A is not true.
[tex]\Delta G=\Delta H-T\Delta S[/tex]
When [tex]\Delta G[/tex] is negative, then the reaction is spontaneous.
[tex]\Delta G=176-0.285T[/tex]
When T<50
Suppose T=49 K
[tex]\Delta G=176-49\times 0.285>0[/tex]
Therefore, [tex]\Delta G is positive[/tex].Hence, the reaction is not spontaneous.
Option B is wrong.
C.T>617K
Suppose T=618 K
[tex]\Delta G=176-0.285\times 618=-0.13<0[/tex]
Therefore, [tex]\Delta G is negative[/tex].Hence, the reaction is spontaneous.
So, option C is true.
D.T<617 K
Suppose T=616 K
[tex]\Delta G=176-0.285\times 616=0.44>0[/tex]
Therefore, [tex]\Delta G is positive[/tex].Hence, the reaction is not spontaneous.
So, option D is not true.
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.
For class 10th
Answer:
Water contains two parts of hydrogen and one part oxygen. Therefore, during the electrolysis of water the amount of hydrogen has collected in one of the test tubes is double than that of the oxygen produced and collected in the other last tube.
The total kinetic energy of a body is known as:
A. Convection
B. Potential energy
C. Thermal energy
D. Temperature
Answer: THERMAL ENERGY
Explanation: thermal is also known as heat and the body contains more of heat
hope it helps
The number of Atoms present in one mole of an element is equal to Avogadro Number. Which One Of the Following contains the greatest number of Atoms? (1)4g He (2)46g Na (3)0.40g Ca (4) 12g He
Answer:
Thus, the element containing the greatest number of atoms is 12 g He. Thus, the correct option is (4) 12 g He. Note: The number of atoms of a compound is Avogadro's number for 1 mole of compound. The number 6.022×1023 is known as Avogadro's number.
Explanation:
(4)✔️ 12 g He
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iammallikaAnswer:
120gram I think so this is the answer if the answer is correct plz mark me as brainliest.
what is chemical reaction?
Answer:
a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
Or
Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
1.25 X 10^24 molecules of chlorine gas react with sodium to form how many grams of sodium
chloride?
2Na + Cl2
--> 2NaCl
Answer:
241.28 g NaCl(s)
Explanation:
Given 1.25 x 10²⁴ molecules of Cl₂ = 1.25 x 10²⁴molecules Cl₂(g)/6.023 x 10²³ molecules/mole = 2.08 mole Cl₂(g)
2Na(s) + Cl₂(g) => 2NaCl(s)
excess 2.08mole ? mole
∴moles NaCl(s) formed from 2.08 moles Cl₂(g) = 2(2.08 mole NaCl(s))
= 4.16 mole NaCl(g) = 4.16 mole NaCl(s) x 58 g NaCl(s)/mole NaCl(s) = 241.28 g NaCl(s)
Which is a constructive process? Rivers carrying sediment down stream, the rusting of a bridge, waves cutting back a beach front, volcanic eruption caused by plate tectonics
Answer:
volcanic eruption caused by plate tectonics.
Explanation:
Constructive process is one in which memories are influenced by some events. When a person tries to retrieve the memory he first click some event which is associated with that memory and then whole flash backs comes to his mind.
What are the uses of iron and it's reasons.
Answer:
Uses of iron
It is used to manufacture steel and also used in civil engineering like reinforced concrete, girders etc. Iron is used to make alloy steels like carbon steels with additives such as nickel, chromium, vanadium, tungsten, and manganese.
Answer:
iron is used to make water pipes.
used for making machines in industries.
used for making steam engine.
Na3N decomposes to form sodium and nitrogen gas at STP. If 13.7 L of nitrogen is produced
how many moles of Na3N was used? (22.4 L = 1 mole of any gas)
2Na3N --> 6Na + N2
Answer: 1.224 moles of [tex]Na_3N[/tex] were used.
Explanation:
We are given:
Volume of nitrogen gas produced = 13.7 L
At STP conditions:
22.4 L of volume is occupied by 1 mole of a gas
Applying unitary method:
13.7 L of nitrogen gas will be occupied by = [tex]\frac{1mol}{22.4L}\times 13.7L=0.612mol[/tex]
For the given chemical reaction:
[tex]2Na_3N\rightarrow 6Na+N_2[/tex]
By Stoichiometry of the reaction:
1 mole of nitrogen gas is produced by 2 mole of [tex]Na_3N[/tex]
So, 0.612 moles of nitrogen gas will be produced from = [tex]\frac{2}{1}\times 0.612=1.224mol[/tex] of [tex]Na_3N[/tex]
Hence, 1.224 moles of [tex]Na_3N[/tex] were used.
WHAT IS KNOWN AS HYBRIDIZATION
[tex] \red{ \bold {\huge{ \textit{ \boxed {{\blue{QUESTION}}}}}}}[/tex]
WHAT IS KNOWN AS HYBRIDIZATION
[tex]\huge\boxed{\fcolorbox{red}{blue}{ ANSWER }}[/tex]
[tex] \orange{\underline{\huge{\bold{\textit{\green{\bf{HYBRIDIZATION}}}}}}} [/tex]
It is the change in the orbitals of the central atom of the molecule to form bonds with other atom if same type or another type.The hybrid orbitals r of same level .
The Hybridization takes place in between orbitals of equal or very less energy levels to form same level of energy in all orbitals.
The orbitals combine is always equal to The number of orbitals formed
The names of hybridized orbitals r kept according to the orbital which r combined to form them
Eg:-sp orbital :- one s and one p combine to form sp orbital
[tex]s {p}^{2} [/tex]orbital :- one s and two p orbitals combine to form it..
[tex]\:\:\:\:\:\:\:\:\star DEVIL005\star[/tex]
Calculate the number of phosphorus atoms in 6.2g of phosphorus
Answer:
9.33 e22
Explanation:
For moles
N=m/M
N=6.2/40
N=0.155
For total no. Of atoms:
Atoms= N × 6.02e23
Atoms= 0.155× 6.02e23
Atoms= 9.33e22
Complete the following blanks on the basis of law of conservation of mass.
1) Na + O2 -----> 2NaO
8 g + 65 g ---> ______
2) 2H2 + O2 → 2H2O
24 g + ____ → 62 g
8g + 65g = 73g
24g + 38g = 62g
Answer:
1)Na + O2 = > 2NaO
8 g + 65 g = > 73g
2) 2H2 + O2 → 2H2O
24 g + 38g→ 62 g
If the sky is actually black, and the water is actually clear, where does the blue color for the sky and water come from?
Answer:
that the water is blue because of the way water absorbs light, the way particles in the water scatter light, and also because some of the blue light from the sky is reflected
Fe-54 = 5.845%
Fe-56 = 91.754%
Fe-58 = 2.119%
(Please help)
Calculate the average atomic mass/ given their percent abundance
Answer:
55.768
Explanation:
The following information is given in this question:
Fe-54 = 5.845%
Fe-56 = 91.754%
Fe-58 = 2.119%
First, we convert from percentage abundance to decimal abundance
Fe-54 = 5.845% = 0.05845
Fe-56 = 91.754% = 0.91754
Fe-58 = 2.119% = 0.02119
To find the average atomic mass of iron (Fe), we multiply each isotopes' decimal abundance by its mass no and find the sum as follows:
Average atomic mass = (0.05845 × 54) + (0.91754 × 56) + (0.02119 × 58)
Average atomic mass = 3.1563 + 51.38224 + 1.22902
Average atomic mass = 55.768
How are conduction, convection, and radiation different? Conduction transfers thermal energy by . Convection transfers thermal energy by . Radiation transfers thermal energy by .
Answer:
See explanation
Explanation:
There are three modes of heat transfer; conduction, convection and radiation.
Conduction refers to the transfer of heat without the actual movement of the particles of matter.
Convection is the transfer of heat by the actual movement of the particles of matter.
Radiation is the transfer of heat without a material medium.
Hence the three modes of heat transfer differ in the actual mechanism by which heat energy is transferred as shown above.
Answer:
The movement of molicules
The movement of a fluid
Electromagnetic Waves
Explanation:
Trust me
Which of the following could be classified as a molecular element?
Question 1 options:
krypton
lithium
nitrogen
calcium
All four are classified as molecular elements.
Answer:
calcium is the correct answer to the question
The body part of a spirogyra is.............
Answer:
The chloroplasts form a spiral around the vacuole and have specialized bodies known as pyrenoids that store starch. The cell wall consists of an inner layer of cellulose and an outer layer of pectin, which is responsible for the slippery texture of the algae.
Explanation:
The body part of a spirogyra is called pyrenoids .hope it is helpful to you
i need to know soon. HELP
PLEASE
Answer:
D..
carbonate and sulphate
Help me please I need this quickly
9. melting point
10. balloons float because they are filled with hydrogen, a gas which is less dense than air.
11. specific gravity
12. element
13. mixture
14. sodium and chlorine
15. cutting of paper
16. condensation
17. 1 and 3
18. heat energy is released
name a food that contain an acid
Answer:
name a food that contain an acid
1. nuts
2. dairy
3. grains
3. meat
these are the foods which contains acids.
hope its helps you
have a great day keep smiling be happy stay safe.
The partial pressure of carbon dioxide in air varies with the seasons. Would you expect the partial pressure in the Northern Hemisphere to be higher in the summer or winter
Answer:
It will be higher in the summer.
Explanation:
Usually, the winter season is more harsh a weather on leaves than summer because it is wet season and thus has less sunlight and this means there will be less photosynthesis reactions and therefore it means the partial pressure will be lesser here unlike in the summer when it is a more warm and dry weather with sunlight where photosynthesis reactions will be more favorable to occur.
Thus, CO2 which is a great component of photosynthesis is used more in the summer and as such the partial pressure in the summer will be higher.
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convert 300g into kg
Answer:
0.3kg
Explanation:
what is displacement?
Answer:
the moving of something form it's places or position
is an atom of a metal?
Answer:
An atom of an element that exhibits typical metallic properties, being typically shiny, with high electrical and thermal conductivity. ... A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
The field around a negatively charged object is symbolized by vectors pointing toward the sphere because a test charge, which is ______ by definition, would travel along such a vector if released in the field.
Positive
Negative
Answer:
Positive
Explanation:
State whether the following statement is true or false. If false, then rewrite
1. Melting of ice is a physical change.
Answer:
True
Explanation:
A physical change is a change of state. So when ice melts it changes from a solid to a liquid so it is a physical change
help me plz!!!!
a. Calculate the solution concentration for each of the HCl samples. The first one has been done for you.
b. As the concentration of the HCl solution increased, did the speed of the reaction increase or decrease?
c. Therefore, as the concentration of a reactant increases, does the rate of the reaction increase or decrease?
d. Do your predictions previous to this investigation agree with your results?
e. Make a general rule about the effects of concentration of reactants on reaction rates.
Answer:
From this solution, you can do the a number question answer.
Which of the following elements has three valence electrons? (2 points)
Li
C
Al
Mg
Answer:
Al
Explanation:
It has 3.
