Answer:
ΔHr = -566kJ/mol
Explanation:
Based on Hess's law, the ΔH of a reaction is the sum of the ΔH's of products times its coefficient subtracting the ΔH of reactants. For the reaction:
2CO(g) + O2(g) → 2CO2(g)
ΔH is:
ΔHr = 2*ΔH CO2 - (2ΔH CO + ΔH O2)
As ΔH CO2 = -393.5kJ/mol; ΔH CO = -110.5kJ/mol and ΔH O2 = 0kJ/mol
ΔHr = 2*-393.5kJ/mol - (2*-110.5kJ/mol)
ΔHr = -566kJ/molWhich two compounds of oxygen are small molecules?
Explain why metals conduct electricity. Refer to structure and bonding in your answer
Answer:
They are electrical conductors because their delocalised electrons carry electrical charge through the metal.
Explanation:
for the second ques
not sure...
NEED ANSWERS ASAP!!! 20 POINTS IF YOU ANSWER ALL QUESTIONS(NO LINKS, SPAMMING OR GUESSING)
What is the name of flower part #10?
Captionless Image
sepal
pollen tube
filament
Stigma
Renewable energy resources are?
A resource that cannot be readily replaced by natural means on a level equal to its use.
Invisible resources
Renewable resources that can be naturally restored.
All the above
To produce perfumes for Man
This is energy that is stored for later use.
kinetic energy
potential energy
mechanical energy
electromagnetic energy.
When fertilization has occurred the fertilized ovule changes and so does the ovary. What do they turn into?
The fertilized ovule turns into the fruit and the ovary turns into the seed.
The ovule grows bigger and the ovary withers.
The fertilized ovule turns into a seed and the ovary turns into the fruit or pod.
The fertilized ovule turns into honey and the ovary turns into nectar.
What is energy?
1 point
moving energy
stored energy
renewable energy
The ability to do work.
Wind-pollinated flowers usually have ______ and ________ petals.
1 point
big ... bright
small .... bright
big ... dull
small ... dull
What is the function of nectar?
To provide food for the flower
To attract pollinators
To attract animals to disperse the fruits
Which of the following devices transforms electrical energy into mechanical energy?
1 point
An e-reader
a fan
a manual pencil sharpener
iPod
Captionless Image
sepal
pollen tube
filament
Stigma
Renewable energy resources are?
A resource that cannot be readily replaced by natural means on a level equal to its use.
Invisible resources
Renewable resources that can be naturally restored.
All the above
To produce perfumes for Man
This is energy that is stored for later use.
kinetic energy
potential energy
mechanical energy
electromagnetic energy.
When fertilization has occurred the fertilized ovule changes and so does the ovary. What do they turn into?
The fertilized ovule turns into the fruit and the ovary turns into the seed.
The ovule grows bigger and the ovary withers.
The fertilized ovule turns into a seed and the ovary turns into the fruit or pod.
The fertilized ovule turns into honey and the ovary turns into nectar.
What is energy?
1 point
moving energy
stored energy
renewable energy
The ability to do work.
Wind-pollinated flowers usually have ______ and ________ petals.
1 point
big ... bright
small .... bright
big ... dull
small ... dull
What is the function of nectar?
To provide food for the flower
To attract pollinators
To attract animals to disperse the fruits
Which of the following devices transforms electrical energy into mechanical energy?
1 point
An e-reader
a fan
a manual pencil sharpener
iPod
its one of these and chillll
How many moles of copper would be needed to make one mole of cu2o?
Answer:
Explanation:
You can view more details on each measurement unit: molecular weight of Copper(I) Oxide or grams The molecular formula for Copper(I) Oxide is Cu2O. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Copper(I) Oxide, or 143.0914 grams.
What is the molecular geometry of a molecule with 2 outer atoms and 3 lone pairs on the central atom?
Answer:
See explanation
Explanation:
The valence shell electron pair repulsion theory states that the number of electron pairs on the valence shell of the central atom of a molecule determines the shape or geometry of the molecule.
For a molecule having two bonding pairs and three lone pairs, the shape should based on a trigonal bipyramid. However, the molecular geometry is linear with a bond angle of 180 degrees.
Commercially available concentrated hydrochloric acid is 37.0% w/w HCl. Its density is 1.18g/ml. Calculate the molarity of concentrated HCl?
Answer:
M = 12.0M
Explanation:
Hello there!
In this case, according to the given by-mass percent of HCl, which can be set up in terms of mass of HCl over mass of solution, we can calculate the molarity, by multiplying by the density to get the mL's of solution and further convert to liters. Moreover, the molar mass of HCl (36.46 g/mol) must be also used to calculate the moles, since molar units requires moles of solute and liters of solution as shown below:
[tex]M=\frac{37.0gHCl}{100g\ sln}*\frac{1.18g\ sln}{1mL\ sln}*\frac{1000mL\ sln}{1L \ sln}*\frac{1molHCl}{36.46gHCl}\\\\M= 12.0M[/tex]
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In science lab, Ellie combined sugar and distilled water. Ellie made
A. a mixture, which must be separated by chemical processes.
B. a compound, which must be separated by chemical processes.
C. a mixture, which can be separated through physical processes.
D. a compound, which can be separated through physical processes.
Answer:
C
Explanation:
What are the symbols (in order) for hydrogen, sodium and nitrogen?
Answer:
H, Na, N
Explanation:
Answer:
H, NA, N
Explanation
Gold is classified as what type of element?
How can the wetland reduce flooding and what impact could this have on future generations?
Answer:
Wetlands trap the surface water, snowmelt, rain, groundwater, and flood water. They then slowly release the water. Wetland vegetations like trees and root mats also help in controlling the speed of flood water and release it slowly on the floodplain.
Explanation:
PLEASE HELP!!
Which statement describes the first step in soil formation?
A: Small, simple plants begin to grow.
B: Parent rock breaks into smaller pieces.
C: Humus begins to mix with sediment.
D: Organic material starts decomposing.
Answer:
B: Parent rock breaks into smaller pieces.
Explanation:
Weathering the first step in the process of soil formation. The process of breaking up off the parent rocks into simple forms, is termed as weathering. The formation of soil is a very gradual and slow process. It takes millions of years for the rocks to become soil. The dead and decaying matter of plants and animals are also included in the rocks. Water, sun, climatic conditions and rain are some of the factors that effect weathering.
Answer:
32
Explanation:
I found it
A short-lived structure formed during a collision is a(n)
a. reagent.
b. catalyst.
c. activated complex.
d. inhibitor.
Answer:
c. activated complex
Explanation:
Chemistry Questions
5) What is matter? Mention the characteristic of particles of matter.
Answer:
As known matter is anything that occupies space and has mass.
HSO4, + NaNo, → HNO2, + Na2SO4
WHAT IS THE BALANCE OF THIS EQUATION
Answer:
H2SO4 + 2NaNO2 → 2HNO2 + Na2SO4
Explanation:
Explanation:
[tex]H _{2} SO _{4} \: + \:2 NaNO_{2} - - - > 2HNO _{2} \: + \: Na _{2}SO _{4}[/tex]
Place 2 in nitrous acid and sodium nitrite to balance the equation as shown above
Potassium chloride dissolved in pure water is an
example of
A) an ionic compound dissolved in a polar solvent
B) an ionic compound dissolved in a nonpolar
solvent
C) a covalent compound dissolved in a polar solvent
D) a covalent compound dissolved in a nonpolar
solvent
Answer:
A) An ionic compound dissolved in a polar solvent
Explanation:
Potassium Chloride's chemical formula is KCl. Most ionic compounds are formed between a nonmetal and a metal. In this case, potassium is acting as the metal and chloride is the nonmetal. Water is a polar solvent due to the electronegativity of the oxygen in the molecule creating a partial negative pole, leaving the hydrogen atoms partially positive. Hence, A is your best answer.
If I helped, a brainliest would be greatly appreciated!
6 NaOH + 2 Al --> 2 Na3AlO3 + 3 H2 If you start with 258 g of Al, how many moles of Na3AlO3 can you make?
Solution :
Assuming all Al will be consumed in the reaction.
From the given equation, 2 mole of Al produce 2 mole of [tex]Na_3AlO_3[/tex].
So, 1 mole of Al produce 1 mole of [tex]Na_3AlO_3[/tex]. .....statement 1)
Number of moles of Al in 258 gram of Al.
[tex]n = \dfrac{mass}{molar\ mass}\\\\n = \dfrac{258}{27}\ moles\\\\n = 9.556 \ moles[/tex]
Therefore, from statement 1) number of moles of [tex]Na_3AlO_3[/tex] produced is also 9.556 moles.
__________ ___________ can release different forms of energy such as electricity or light, in addition to the release of heat energy. *
Changes in Matter
Exothermic Reactions
Endothermic Reactions
Kinetic Energy
Answer:
___Exothermic Reactions_____can release different forms of energy such as electricity or light, in addition to the release of heat energy. *
Need some help on this.
20 pts and brainliest
HELP ME PLEASE
Iron is a metal. Which property would you expect it to have?
A. It is a bad conductor of heat.
B. It is a gas at room temperature,
C. It is a good conductor of electricity
D. It has little or no shine
Answer: it is a good conductor of electriciy tht is what wires are made of and it is a good conductor of heat so it will be able to handle the heat from the electricity
Explanation:
Answer:
Iron is a shiny, bright white metal that is soft, malleable, ductile and strong. Its surface is usually discolored by corrosion, since it combines readily with the oxygen of the air in the presence of moisture. In absolutely dry air, it does not rust
Explanation:
I hope it helps
What volume of He is occupied by 2.50 mol of He at 25.0°C and a pressure of 0.980 atm?
Answer: The volume occupied by He is 62.4 L
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 0.980 atm
V = Volume of gas = ?
n = number of moles = 2.50 mol
R = gas constant =
T =temperature =[tex]25.0^0C=(25.0+273)K=298.0K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{2.50mol\times 0.0821 Latm/K mol\times 298.0K}{0.980atm}=62.4L[/tex]
Thus the volume occupied by He is 62.4 L
360.0 g piece of iron is dropped into 425 mL of water at 24.00 °C. The final temperature of the water was measured as 45.70 °C. Calculate the initial temperature of the metal.
Answer:
T(initial) = 241.4˚C
Explanation:
∑q = q(metal) + q(water) = 0*
Q(metal) = (m∙c∙ΔT)Fe = 360g x 0.444j/g˚C x (45.7˚C – T(initial)) = 159.84j/˚C(45.7˚C – T(initial)) = 7304.69 j – 159.84j/˚C x T(initial)
Q(water) = (m∙c∙ΔT)water = 425g x 4.184j/g˚C x (45.7˚C - 24˚C) = 38,586.94 joules
∑[Q(metal) + Q(water)] = 7304.69j -159.84j/˚C x T(initial) + 38586.94j = 0
=> 159.84 x T(initial)j/˚C = 38586.94j
=> T(initial) = 38586.94j / 159.84j/˚C = 241.4˚C
____________________________________
*Initial equation is from Heat Loss = Heat Gained (Conservation of Energy) That is, Heat lost + (- Heat gained) = 0
=> ∑(heat loss by metal) + (- heat gained by water) = 0
using heat transfer equation with temperature change
=> mcΔT(metal) + (-mcΔT(water) = mcΔT(metal) - (mcΔT(water) = 0
What do these elements make:
neodymium, rhenium and sulfur
Answer:
Neodymium makes flints inside of lighters. It also takes away the green color off of glass. Rhenium is added with tungsten and molybdenum which makes filaments for lamps. Sulfur makes sulfuric acid which makes batteries and cleaners and can process ores.
Explanation:
An interesting fact for each element:
Neodymium is known for the atomic symbol Nd and the atomic number 60.
Rhenium is known for the atomic symbol Re and the atomic number 75.
Sulfur is known for the atomic symbol S and the atomic number 16.
I hope the Answer answers your question. I gave you some facts to remember those elements in the periodic table!
Neodymium(III) bromide, NdF3, neodymium(III) chloride, NdCl3, neodymium(III) bromide, NdBr3, and neodymium(III) iodide, NdI3, are the results of its reactions with fluorine, chlorine, bromine, and iodine.
Learn more about neodymium brainly.com/question/18012256
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BRAINLIESTT
The pH of a solution is 8.43. What is it {H3O+}concentration?
A. 3.7 x 10-3
B. 2.7 x 10-6
C. 1.0 x 10-14
D. 1.0 x 10-8.43
Answer: D. [tex]1.0\times 10^{-8.43}M[/tex]
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydronium ion concentration.
[tex]pH=-\log [H_3O^+][/tex]
Putting in the values:
[tex]8.43=-\log[H_3O^+][/tex]
[tex][H_3O^+]=10^{-8.43}=3.7\times 10^{-9}M[/tex]
Thus [tex][H_3O^+][/tex] concentration is [tex]10^{-8.43}M[/tex]
Which of the following is NOT a feature of Iron (III) oxide?
a. forms a protective barrier
b. falls off in flakes
c. red-orange in color
d. requires moisture to form
Answer:
I think its it is A
Explanation:
Rust is red in colour, falls off in flakes, and forms when iron is wet. By process of elimination, it must be B.\
can i get brainly
two clear solutions are mixed together in a beaker. which would most likely indicate a chemical change had occurred?
a. separation of two liquids
b. increase in volume of the liquid in the beaker
c. increase in mass of the liquid in the beaker
d. change of colour of the liquid in the beaker
Explanation:
I am not sure without knowing the name of the solutions. But according to me it can be happen which are D bcz when two solutions for e.g acid and base are mixed together, it changes its colour an form salts.
Explain why the sharp edge of knife cuts easily through bread than the blunt of the same knife
Answer:
because its sharper...
Match the word to the definition
Question 1 options:
simple diffusion
osmosis
facilitated diffusion
1.
Molecules move from high to low concentration
2.
Molecules move from high to low concentration with a transport protein
3.
Diffusion of water through a selectively permeable membrane
what you think would happen if global warming caused a decrease in all clouds
Answer:
Global warming is expected to cause changes in the amount of cloud cover, and the height and thickness of these clouds in the future, shifting the balance between the parasol and blanket effects of clouds. The knock-on effect this will have on temperature is known as cloud feedback
Explanation:
Global warming is expected to cause changes in the amount of cloud cover, and the height and thickness of these clouds in the future, shifting the balance between the parasol and blanket effects of clouds. The knock-on effect this will have on temperature is known as cloud feedback
Please help me on this!!
Answer:
OK
Explanation:
OK
Question 5 (10 points) How many moles of Cuci, are needed to react with 4 moles of Al? + 3CuCl2 (aq) → Cu (s) + 2AlCl3 (24) O a 6 moles 1 mole 2 moles OO 8 moles
Answer:
A. 6 moles
Explanation:
This question contains a chemical reaction between aluminum (Al) and Copper(II)Chloride to give copper and aluminum chloride. The unbalanced chemical equation is as follows:
Al (s) + 3CuCl2 (aq) → Cu (s) + 2AlCl3
To balance the equation, we use coefficients in front of Al and Cu to ensure the amount of both are uniform on both sides of the equation. The balanced equation is as follows;
2Al (s) + 3CuCl2 (aq) → 3Cu (s) + 2AlCl3
From the balanced equation, 2 moles of Al reacts with 3 moles of CuCl2
Hence, 4 moles of Al will react with (4 × 3) ÷ 2
= 12 ÷ 2
= 6 moles of CuCl2
2. How many moles of Hydrogen gas are needed to produce 4 moles of water?
2 H2(g) + 1 O2(g) → 2 H2O(l)
Answer:
4 mol H₂
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesAqueous Solutions
States of matterStoichiometry
Using Dimensional AnalysisAnalyzing reactions RxNExplanation:
Step 1: Define
[RxN - Balanced] 2H₂ (g) + O₂ (g) → 2H₂O (l)
[Given] 4 mol H₂O
[Given] mol H₂
Step 2: Identify Conversions
[RxN] 2 mol H₂ (g) → 2 mol H₂O (l)
Step 3: Stoichiometry
[DA] Set up conversion: [tex]\displaystyle 4 \ mol \ H_2O(\frac{2 \ mol \ H_2}{2 \ mol \ H_2O})[/tex][DA] Multiply [Cancel out units]: [tex]\displaystyle 4 \ mol \ H_2[/tex]