Answer:
Birth rate, death rate, emigration, immigration, or a census.
Explanation:
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
How can you calculate the instantaneous rate of a reaction from a graph of concentrations over time?
What amount of SeC16 is needed to produce 4.45 mol of chlorine gas in the
reaction Seclo +0 218) —SeO, +3Cl2te)?
2.85 mol
0.95 mol
5.70 mol
8.55 mol
1.49 mol
Answer:
1.48 moles of SeCl6 are needed
Explanation:
Based on the reaction:
SeCl6 + O2 → SeO2 + 3Cl2
1 mole of SeCl6 reacts producing 3 moles of Cl2.
To solve this question we need to use the conversion factor:
1mol SeCl6 = 3mol Cl2
As we want to produce 4.45 moles of Cl2, we need:
4.45 mol Cl2 * (1mol SeCl6 / 3mol Cl2) =
1.48 moles of SeCl6 are needede) Hydrogen gas is a non-metal and can be prepared in a laboratory Explain why hydrogen gas is collected over water.
Answer:
to collect pure hydrogen and avoid mixing with air
The number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be
Options:
814 g
0.125 g
0.278 g
337 g
The number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be 0.125g.
How to calculate mass?The mass of a substance can be calculated by multiplying the number of moles by its molar mass.
However, the number of moles of helium must be calculated as follows:
PV = nRT
Where;
P = pressureV = volumen = no of molesR = gas law constantT = temperature0.985 × 0.785 = n × 0.0821 × 301
0.773 = 24.7n
n = 0.773 ÷ 24.7 = 0.031moles
mass of He = 0.031 × 4 = 0.125g
Therefore, the number of grams of helium in a balloon at a pressure of 99.8 kPa, a temperature of 301 K, and a volume of 0.785 L would be 0.125g.
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Calculate K for 2CO2(g) ⇔ 2CO(g) + O2(g)
given that the equilibrium concentrations of carbon monoxide, oxygen and carbon dioxide are 2.0 x 10-6 M, 1.0 x 10-6 M, and 0.25 M respectively.
Explanation:
here's the answer to your question
Plz help I will give brainliest
Answer:
1. Fr
2. cl
3.H20
4.2 mole
5. 3
6. c
what is the reactant(s) in the chemical equation below
3CO(g) + Fe2O3(s) 2Fe(s) + 3CO2(g)
Answer:
the reactants are carbon dioxide ,iron, oxygen
Under certain conditions, the substance mercury(II) oxide can be broken down to form mercury and oxygen. If 24.1 grams of mercury(II) oxide react to form 22.3 grams of mercury, how many grams of oxygen must simultaneously be formed? Grams oxygen
Answer:
1.76 g
Explanation:
2HgO(s) ==> 2Hg(l) + O2(g)
Number of moles of Hg = 22.3 g/ 201g/mol
= 0.11 moles
From the reaction equation;
2 moles of Hg is formed alongside 1 mole of oxygen
Hence;
0.11 moles of Hg forms 0.11 moles × 1/2
= 0.055 moles of oxygen
Mass of oxygen formed = 0.055 moles of oxygen × 32g/mol = 1.76 g
The first atmosphere a. consisted mainly of water, carbon dioxide, carbon monoxide, and methane. b. was replaced by a secondary atmosphere that, arguably, consisted partially of gases brought to the Earth by comets. c. was replaced by a secondary atmosphere only after the Earth developed gravity, which helped deflect the solar wind. d. dissolved into the Earth's oceans before it was replaced by a second atmosphere.
Answer:
Hence the correct option is option b - was replaced by a secondary atmosphere that, arguably, consisted partially of gases brought to the Earth by comets.
Explanation:
The first atmosphere was formed during the formation of the world.
But the secondary atmosphere formed mainly 2. billion years ago by earth's internal volcanic activity, or by the buildup of fabric from comet impacts.
2.
In photosynthesis, which substances are used up, which are produced and which are necessary
but remain unchanged after the reaction?
used up
produced
remain
A
carbon dioxide
water
oxygen
A
8
chlorophylt
carbon dioxide
water
с
oxygen
starch
cellulose
D
water
oxygen
chlorophyll
D. Water is used up, Oxygen is produced and Chlorophyll is necessary, but remains unchanged.
A 100 g sample of potassium chlorate, KCIO3(s), is completely decomposed by heating:
2 KCIO3(s) 2 KCl(s) + 3 O2(g)
The oxygen is collected at 89 kPa and 23°C. Calculate the volume, in litres, of oxygen that would be
produced during the decomposition of this sample.
4. Magnesium is the limiting reactant in this experiment. Calculate the theoretical yield of MgO for each trial.
5. Determine the percent yield of MgO for your experiment for each trial.
6. Determine the average percent yield of MgO for the two trials.
Answer: The average percent yield of MgO is 98.59 %.
Explanation:
The chemical equation follows:
[tex]2Mg(s)+O_2(g)\rightarrow 2MgO(s)[/tex]
For Trial 1:The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of Mg = 0.411 g
Molar mass of Mg = 24.3 g/mol
Plugging values in equation 1:
[tex]\text{Moles of Mg}=\frac{0.411g}{24.3g/mol}=0.0170 mol[/tex]
By the stoichiometry of the reaction:
If 2 moles of Mg produces 2 moles of MgO
So, 0.0170 moles of Mg will produce = [tex]\frac{2}{2}\times 0.0170=0.0170mol[/tex] of MgO
We know, molar mass of [tex]MgO[/tex] = 40.3 g/mol
Putting values in equation 1, we get:
[tex]\text{Mass of }MgO=(0.0170mol\times 40.3g/mol)=0.685g[/tex]
The percent yield of a reaction is calculated by using an equation:
[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(2)
Given values:
Actual value of the product = 0.675 g
Theoretical value of the product = 0.685 g
Plugging values in equation 1:
[tex]\% \text{yield}=\frac{0.675g}{0.685g}\times 100\\\\\% \text{yield}=98.54\%[/tex]
Hence, the % yield of the product is 98.54 %
For Trial 2:Given mass of Mg = 0.266 g
Molar mass of Mg = 24.3 g/mol
Plugging values in equation 1:
[tex]\text{Moles of Mg}=\frac{0.266g}{24.3g/mol}=0.011 mol[/tex]
By the stoichiometry of the reaction:
If 2 moles of Mg produces 2 moles of MgO
So, 0.011 moles of Mg will produce = [tex]\frac{2}{2}\times 0.011=0.011mol[/tex] of MgO
We know, molar mass of = 40.3 g/mol
Putting values in equation 1, we get:
[tex]\text{Mass of }MgO=(0.011mol\times 40.3g/mol)=0.443g[/tex]
The percent yield of a reaction is calculated by using an equation:
[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(2)
Given values:
Actual value of the product = 0.437 g
Theoretical value of the product = 0.443 g
Plugging values in equation 1:
[tex]\% \text{yield}=\frac{0.437g}{0.443g}\times 100\\\\\% \text{yield}=98.64\%[/tex]
Hence, the % yield of the product is 98.64 %
Average of a measurement is calculated by given formula:
[tex]Average=\frac{M_1+M_2}{2}[/tex]
where,
[tex]M_1[/tex] = percentage yield for Trial 1 = 98.54 %
[tex]M_2[/tex] = percentage yield for Trial 2 = 98.64 %
Putting values in above equation, we get:
[tex]Average=\frac{98.54+98.64}{2}=98.59\%[/tex]
Hence, the average percent yield of MgO is 98.59 %.
Any individual offspring produced through a sexual reproduction is always,
Answer:
Any individual offspring produced through asexual reproduction is always: genetically identical to its parent. made up of cells with a cell wall. different from all of its siblings
What is the atomic number of the atom in the diagram above please ?
Answer:
5
Explanation:
The atomic number is the number of protons in an atom. Protons are the positively charged particles in the nucleus. The number of protons define the identity of an element. An element with 5 protons is Boron, no matter how many neutrons may be present.
The atomic number of the atom shown in the diagram is 5.
What is the atomic number?The atomic number of an element refers to the number of protons in the nucleus of its atoms. It uniquely identifies an element and determines its chemical properties.
In the diagram, there are 5 proton numbers in the nucleus of the atom. In other words, this means that the atomic number of the atom is 5.
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A cylinder container with a diameter of 23.0 cm and a height of 140 cm contains N2O at a pressure of 108 kpa and temperature of 294 K. How many grams of N2O gas are in the cylinder?
Answer:
113.17 g
Explanation:
This can be solved using the Ideal Gas Equation:
PV=nRT
First step is to calculate the volume of the cylinder in L:
V=πr²h
V= π (11.5)² (140)
V= π (132.25) (140)
V = π (18.515)
V = 58,166.588 cm³ = 58.2 L
Then, convert kpa into atm:
1 kpa = 0.00987 atm
108 kpa = 1.06588 atm
Then, plug all of your values into the Ideal Gas Equation to solve for moles:
(1.06588)(58.2)=n(0.082057)(294)
62.034=n(24.125)
2.571357513=n
Finally, convert the moles into grams
2N = 28.0134 amu
O = 15.999 amu
_______________
44.0124 amu
(2.571357513moles)(44.0124 amu) = 113.17 g
By which process aqua fortis is manufactured
1) Haber's process
2) Ostwald process
3) Contact process
4) Deacon's process
Answer: Aqua fortis is also known as Nitric Acid
Explanation: and the process in making aqua fortis is THE OSTWALDS PROCESS
detailed explanation by me
ammonia is also used in this process, which is reacted with oxygen and water and a catalyst platinum.
HOPE THIS HELPSS!!!
HELP PLEASE 15 POINTS
The rate law for a reaction is found to be rate = k[X]4. By what factor does the rate increase if [X] is doubled?
Write a balanced molecular equation describing each of the following chemical reactions.
(a) Solid calcium carbonate is heated and decomposes to solid calcium oxide and carbon
dioxide gas.
(b) Water vapor
Answer:
don't know..............
Color of the CuCl2 hydrate before heating:
hydrated cucl2 have blue-green colour
PLZ HELP ME WITH MY WORK
How many different elements are there in the molecule C8H11NO2,?
A. 21
B. 2
c. 11
D. 4
Answer:
option C 11
is the correct answer
Organisms do not adapt as a result of competition for resources.
Answer:
The given statement is False.
The organisms adapt as a result of competition for resources. Different places have different organisms suited for that particular places.
The animals living at a particular place compete for the resources available and the nature selects the organism that has won the competition for resources.
The organisms are evolved as a result of competition for resources
Answer:
I just wanted to say the other person is totally right.
this statement is false.
Elements in the same period Question 7 options: A) form bonds with the same type of elements. B) have the same number of protons. C) have the same number of valence electrons. D) have the same principal quantum number.
D is the answer .. I have send u pic also
Heat transfer takes place when:
A. there is a temperature difference.
B. conduction or convection occurs, but not radiation.
OC. thermal energy is present.
D. None of these
Answer:
A. There is a temperature difference
Explation:
Whenever there is a temperature difference, heat transfer occurs. Heat transfer may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice chest.
Answer:
A.) there is a temperature difference
Explanation:
I got it correct on founders edtell
balanced chemical equation:Copper( ii) oxide solid +dilute sulphuric acid
Answer:
CuO + H2SO4 = CuSO4 + H2O
Reaction type: double replacement
A sample of gas occupies 1.2 L at 12.0oC. Assuming pressure remains the same, what would be the volume (in L) of this gas at 67oC?
A.
1.4
B.
1.0
C.
0.2
D.
5.0
E.
6.7
Answer:
e.
6.7
hope it help
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What effect does temperature have on reaction rate?
A. An increase in temperature does not change the reaction rate,
B. An increase in temperature keeps the reaction from stopping.
C. An increase in temperature speeds up the reaction rate.
D. An increase in temperature slows the reaction down.
The dehydration of a secondary alcohol, like cyclohexanol, is a mechanism that occurs Choose... . First, the alcohol is protonated to Choose... , creating Choose... intermediate. Then, a Choose... is removed, moving the electrons from that bond to make a Choose... bond.
Answer:
Mechanism
explanation:
have a great day!
An example of basic research is A) the development of new plastics that can be recycled. B) the study of the relationship between the amount of automobile emissions gases in the atmosphere and the decomposition of atmospheric ozone. C) the study of the composition of the atom. D) the design of new batteries for electric cars. E) the study of natural compounds in sea animals to look for new molecules that can be used for medicine.
Answer:
C) the study of the composition of the atom.
Explanation:
A research can be defined as a systematic investigation or careful consideration of study with respect to a particular problem using scientific methods such as collection of data, documenting critical information, analysis of data, and the establishment of facts in order to reach new conclusions.
Similarly, a basic research is an approach to research that's typically theoritical and it's aimed at developing a theory, searching for the truth or gain a better understanding about a phenomenon, subject, or basic laws on nature.
In this context, an example of basic research is the study of the composition of the atom.
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.
Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
why is unit of pressure called a derived unit ?? 2) how do you measure the volume of milk?
1. Unit of pressure called a derived unit because it is a combination of base units (kg·m^-1·s^·2).
2. We measure the volume of milk by a instrument called Milk Lactometer.
