Answer: 2 mol of NaOH
Explanation:
The balanced chemical equation for the reaction is:
Na2O + H2O --> 2NaOH
Looking at this, we can see that 1 mol of Na2O will react with 1 mol of H2O to produce 2 mol of NaOH
How many atoms in total are present in sucrose C12H2011 weighs 1.4 mg
Answer:
2.46×10²¹atoms
Explanation:
[tex]molar \: mass \: of \: the \: sucrose = 12(12) + 22(1) + 11(16) \\ = 144 + 22 + 176 \\ = 342g {mol}^{ - 1} \\ mole = \frac{1.4 \times {10}^{ - 3} }{342} \\ = 4.09 \times {10}^{ - 6} \\ number \: of \: atoms = 4.09 \times {10}^{ - 6} \times 6.022 \times {10}^{23} \\ = 2.46 \times {10}^{21} atoms[/tex]
Consider these equations:
2S (s) + 3O2 (g)→2SO3 (g), ΔH = −792 kJ
2S (s) + 2O2 (g)→2SO2 (g), ΔH = −594 kJ
2SO2 (g) + O2 (g)→2SO3 (g), ΔH =?
What is the missing ΔH?
a. −294 kJ
b. −198 kJ
c. +198 kJ
d. +294 kJ
Answer: (B) −198 kJ.
SECOND TERM 2021/2022 HOLIDAY ASSIGNMENT
SUBJECT: CHEMISTRY CLASS SS1
1 (a) Define a salt
(b) The basicity of tetraoxosulphate VI acid is 2. Explain this statement with equation showing
the reaction between the acid and potassium hydroxide
2. Define buffer solution and give two uses of buffer solutions.
3. Explain and give an example each of
(a) Hygroscopy (b) Efflorescence (c) Deliquescence
4. The concentration of hydrogen ion H⁺ in two solutions are:
(a) 1 x 10⁻³moldm⁻³ and (b) 6 x 10⁻⁹moldm⁻³
What is the pH of each solution?
5. (a) Give three crystalline and four non-crystalline allotropes of carbon
(b) Give three differences between the two main crystalline allotropes of carbon.
1.
a) Salt: any chemical compound formed from the reaction of an acid with a base, with all or part of the hydrogen of the acid replaced by a metal or other cation.
Acid + alkali → salt + water
b)
Tetraoxosulfate (VI), SO2−4,SO42−, is the second conjugate base from the dissociation of sulfuric acid, H2SO4.H2SO4. This acid is a diprotic acid and thus can donate two protons in an aqueous solution to form HSO−4HSO4− after the first dissociation and SO2−4SO42− after the second dissociation.
The fact that tetraoxosulfate (VI) is dibasic means in terms of Brønsted-Lowry acid-base theory, the ion can accept two protons, or in other words, the parent acid donates two protons upon dissociation. This can be shown by the equation of the reaction between the parent sulfuric acid and potassium hydroxide where two hydrogens are replaced:
H2SO4+2KOH → K2SO4+2H2O
2. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many systems that use buffering for pH regulation.
For example, blood in the human body is a buffer solution.
Buffer Solutions are used for fermentation in the making of alcohol
I've only answered 1 & 2
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Answer:
a reaction that can occur in both forward and reverse directions at the same time.
Explanation:
This is because ↓
A reversible reaction is a reaction in which the conversion of reactants to products and the conversion of products to reactants occur simultaneously. A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B.
Hope this helps =)
If 162.35 g aluminum hydroxide are dissolved in 6750 mL of solution, what is the concentration of the solution?
If 162.35 g aluminum hydroxide are dissolved in 6750 mL of solution, the concentration of the solution is 0.308M
How to calculate concentration?The concentration of a solution can be calculated using the following formula:
Molarity = no of moles ÷ volume (L)
However, the number of moles in 162.35g of Al(OH)3 must be calculated as follows:
Molar mass of Al(OH)3 = 78g/mol
no of moles = 162.35g ÷ 78mol
no of moles = 2.08mol
Molarity = 2.08mol ÷ 6.75L
Molarity = 0.308M
Therefore, if 162.35 g aluminum hydroxide are dissolved in 6750 mL of solution, the concentration of the solution is 0.308M.
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The percentage of water vapor present in the air compared to that required for saturation is the ____.
Answer:
30%
Explanation:
The relative humidity is the water-vapor content of the air relative to its content at saturation. Saturated air, for example, has a relative humidity of 100 percent, and near the Earth, the relative humidity very rarely falls below 30 percent.
Suppose that an individual's arm is cut, and because of this injury, bacteria are able to gain entry to the body and cause disease. What type of defense has been breached (overcome)?
adaptive defense
physical defense
chemical defense
Answer:
Physical :)
Explanation:
Skin works as a shield to the outside elements and does a good job of keeping the bad stuff out. :)
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What is the oxidation number of chromium in sodium dichromate, na2cr2o7?.
Answer:+6
Explanation:Oxygen always has an ON of -2 so when there’s O7 the total is -12. Sodium is in group 1 so has an ON of +1 that means with two of them it’s overall ON is +2. When you combine the two that equals -12 but you want it to equal 0. So it would be +12. Considering there are two chromium present you would divide that by 2 making the answer +6.
Explain what the color change indicated about the changes in the concentrations of Co(H2O)62+ and CoCl42– in each trial.
Trail one
starting color: purple
added 3 drops of Hcl(aq)
end color:blue
Trail two
start color is :blue
added 3 drops of AgNOv3(aq)
and White stuff forms at the bottom.
end color is: light pink
Addition of HCl leads to te formation of blue CoCl4^2– while the addition of AgNO3 leads to the formation of pink Co(H2O)6^2+.
What is equilibrium?Dynamic equilibrium is said to have been attained in a reaction when the rate of forward reaction is equal to the rate of reverse reaction. Now we have the equilibrium as shown in the image attached.
When we add HCl as in trial 1, the equilibrium position is shifted to the left and blue CoCl4^2– is formed. When we add AgNO3, the Cl^- is precipitated out of solution and the equilibrium shifts towards the left to yield pink Co(H2O)6^2+.
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How many energetically equivalent ways can you distribute the particles in system a?.
The number of energetically equivalent ways that one can distribute the particles in system A and B are 1 and 6 respectively.
How to calculate the number of ways?From thx complete information, system A has only 1 distribution that's possible.
For system B, the number of ways will be:
= 3 × 2 × 1
= 6
In conclusion, the correct options are 1 and 6 respectively.
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What amount of heat is required to increase the temperature of 75.0 g of water from 22.3˚C to 36.1˚C?
Answer:
4332.5 j
Explanation:
Specific heat of water is 4.186 j /g-C
4.186 j / g-C * 75 g * (36.1-22.3 C) =
Draw the lewis structure of sf2, showing all lone pairs.
Answer:
Number of valence electrons in two F atom = 2(7) = 14
Total number of valence electrons = 6 + 14 = 20 electrons
Placing a bonding pair of electrons between the atoms to form the chemical bonds.
Electrons used in bonding = 4
The remaining electrons are used as a lone pair for central or terminal atoms to achieve an octet to finish the Lewis dot structure.
Electrons used as a lone pair = 20 - 4 = 16
Explanation:
hope this helps
What is the average mass for
Answer:
zzzzzzzZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
Of the following substances, which one will heat up the FASTEST?
Ammonia (4.70 J/g°C)
Aluminum (0.90 J/gºC)
Gold (0.13 J/gºC)
Ethylene glycol (2.42 J/g°C)
A. Ethylene glycol
B. Aluminum
C. Ammonia
D. Gold
The concentration of A is initially 0.150 M before it proceeds to equilibrium. The system is at 298 K. What is the equilibrium concentration of B
For a concentration of is initially 0.150 M before it proceeds to equilibrium, the equilibrium concentration of B is mathematically given as
x=3.0*10^{-7}m
What is the equilibrium concentration of B?Generally, the equation for the change in Gibbs free energy is mathematically given as
dG=-RTInK
Therefore
31.5*10*^{3}=-(8.314)(298)(ink)
K=3*10^(-6)
Eqution
A--->B
K=x/0.1-x
x=3.0*10^{-7}m
In conclusion, the equilibrium concentration
x=3.0*10^{-7}m
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If 25.0 g of NO are produced how many liters,at STP,of nitrogen gas are used?
Answer:
9 1/3 liters
Explanation:
N2 + O2 = 2 NO
Find mole weights from table of elements
N =14
O =~16 30 gm is a mole
22.4 l / mole for gases at STP
22.4 * 25/30 = 18 2/3 Liters of NO
but since Nitrogen is N2 it will take 1/2 s much = 9 1/3
*** EDITED ***
According to the stoichiometry and STP conditions if 25.0 g of NO are produced 2269 liters of nitrogen gas are used.
What is stoichiometry?It is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.1 mole of nitrogen gives 2 moles of NO, thus as per ideal gas equation which on substitution gives V=1×8.314×273/1=2269.722 liters.
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What is the 2nd step in the process of natural selection?
Answer: Selection proper
Explanation:
it's an anti-chance process, but subject to many constraints
Sodium combines with water to produce sodium hydroxide and hydrogen gas. which word equation represents this violent reaction? sodium hydroxide water right arrow. sodium hydrogen sodium water right arrow. sodium hydroxide hydrogen sodium hydrogen right arrow. sodium hydroxide water sodium sodium hydroxide right arrow. water hydrogen
Answer:
B.) sodium water right arrow. sodium hydroxide hydrogen
Explanation:
Reactants are listed before the arrow and products are listed after the arrow. This symbolizes the reactants turning into the products.
Reactants --> Products
Reactants are the molecules which react with each other to make new molecules. Since sodium and water are being combined, they are the starting molecules. Products are the molecules made after a reaction occurs. Sodium hydroxide and hydrogen gas are produced, making them the ending molecules. The balanced chemical equation is:
2 Na⁺ (s) + 2 H₂O (l) --> 2 NaOH (s) + H₂ (g)
Draw the organic products of the reaction shown. Draw hydrogens on oxygen and nitrogen where appropriate and draw charges where needed.
The products of chemical reactions are made up of the atoms of the reactants.
What are organic products?Organic products are chemical compounds that are obtained in a reaction in which there are organic compounds or elements as reactants. The basic types of organic chemical reactions are:
Addition reactions.Elimination reactions.Substitution reactions.Organic redox reactions.How to identify an organic product?To identify an organic product we must take into account that all organic chemical compounds have carbon in their composition.
Note: This question is incomplete because there is some information missing. However I can answer it based on my general prior knowledge.
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Sodium Hydroxide, which is a base, has a pH of _____
a
2
b
3
c
14
d
6
Answer:
c
Explanation:
Given that sodium hydroxide is a base, it's pH has to be above pH 7. Thus, option c is the correct option.
On the other hand, acids have a pH of lesser than 7 while pure water has a pH of 7. All the other options have a pH of less than 7, indicating that they are acids.
3.0 Liters of gas at a pressure of 0.90 atm is compressed to 2.0 atm.
What is the new volume?
Answer:
5.5 L
Explanation:
6. Zn + 2HCl → ZnCl2 + H2 How many moles of HCl are produced from the reaction of 2.25 moles of zinc?
Answer:
E. 16.6 mol HCl
Explanation:
The equation for the reaction is;
Zn + 2 HCl --> ZnCl2 + H2
From the reaction 2 moles of HCl produces 1 mole of ZnCl2
Therefore; 8.3 moles of ZnCl2 will be produced by;
= 8.3 moles ×2
= 16.6 Moles of HCl
Therefore; E. 16.6 mol HCl
Potassium chlorate decomposes to form potassium chloride and oxygen according to the following
equation:
2 KCIO3(s) + 2 KCl(s) + 3 O2(g)
How many grams of oxygen are produced if 244 grams of potassium chlorate decompose and 148
grams of potassium chloride are produced?
O 1.65 g
O 0.607 g
0 96.0 g
O 392 g
Answer:
O 392 g
Explanation:
39.2 grams of oxygen (O2) can be produced.
The concept stoichiometry is used here to determine the grams of oxygen produced. The amount of oxygen produced from the decomposition of 244 grams of potassium chlorate is 96.0 g . The correct option is C.
What is stoichiometry?The stoichiometry is an important concept in chemistry which helps us to use the balanced chemical equation to calculate the amount of reactants and products. Here we make use of the ratios from the balanced equation. It help us to understand how much substance is needed or present.
Here the balanced reaction is:
2 KCIO₃(s) + 2 KCl(s) + 3 O₂(g)
2 moles of KCIO₃ = 2(39 + 35.5 + 3 × 16) = 245 g
3 moles of O₂ = 3 × 2 × 16 = 96 g
245 g KCIO₃ produces 96 g O₂
Therefore 245 g gives 96 × 244/245 = 95.6 g ≈ 96.0 g
Thus the correct option is C.
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A sample of an ideal gas at 1.00 atm and a volume of 1.96 L was placed in a weighted balloon and dropped into the ocean. As the sample descended, the water pressure compressed the balloon and reduced its volume. When the pressure had increased to 15.0 atm, what was the volume of the sample
Answer: 0.130 L
Explanation:
How many moles in 16 grams of oxygen?
Answer:
Half mole or 0.5 moles
__________________________________________________________
SolveOxygen has a molar molar mass of 32 g.
This means that O2 will have half that amount of grams, half-mole-substance.
6.022*10^23 molecules are present in one mole of any substance, so half it for O2.
6.022 × 10²³ [tex]-- >[/tex] 3.011 × 10²³
And simplified, that would make your answer 0.5 moles.
________________________________________________________
Questions?Ask in the comments box, please.
Part of the complement system of defense is opsonization. This process
causes the pathogen to become trapped in mucus.
coats the pathogen exterior so that it is recognized by the host's phagocytes.
creates an acidic environment that prevents pathogen attachment
causes holes to form in the pathogen's cell walls.
Answer:
The correct answer is coats the pathogen exterior so that it is recognized by the host's phagocytes. :)
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how many molecules of oxygen are contain in 100 ml of air at NTP? (air contains 21% oxygen by volume
Answer:
600
Explanation:
because if there's 6 molecules in each then 6×100 is 600
which has a positive impact on land
a.composing
b. deforestation
c. mining
d. urbanization
giving brainiest
[tex]\huge\tt\fbox\pink{↪Answer:–}[/tex]
[tex]▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬[/tex]
[tex]\red\bigstar\:Explanation [/tex]
Option c Deforestation.[tex]▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬[/tex]
I hope it will help you.Answer:
In some cases, changes in land use may have positive effects, such as increasing habitat (as a result of deliberate habitat restoration measures) and reclamation of previously contaminated lands for urban/suburban development.
Explanation:
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3. describe natural sources of radiation. infer some of the dangers that radiation can impose.
Answer:
All of us are exposed to radiation every day, from natural sources such as minerals in the ground, and man-made sources such as medical x-rays. According to the National Council on Radiation Protection and Measurements (NCRP), the average annual radiation dose per person in the U.S. is 6.2 millisieverts (620 millirem).
Explanation:
The gas in a balloon occupies 2.25 L at 298 K and 300 kPa. At
what temperature will the balloon expand to 3.50L and 2.17 atm?
If a gas in a balloon occupies 2.25 L at 298 K and 300 kPa, the temperature at which the balloon expand to 3.50L and 2.17 atm is 345.23K.
How to calculate temperature?The temperature of an ideal gas can be calculated using the following formula:
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressureP2 = final pressureV1 = initial volumeV2 = final volumeT1 = initial temperatureT2 = final temperatureAccording to the information given in this question;
P1 = 300kpa = 2.96 atmP2 = 2.17 atmV1 = 2.25LV2 = 3.50LT1 = 298KT2 = ?2.96 × 2.25/298 = 2.17 × 3.5/T2
0.022T2 = 7.595
T2 = 7.595 ÷ 0.022
T2 = 345.23K
Therefore, if a gas in a balloon occupies 2.25 L at 298 K and 300 kPa. the temperature at which the balloon expand to 3.50L and 2.17 atm is 345.23K.
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