Answer:
When magnesium burns, it combines with oxygen (O2) from the air to form magnesium oxide (MgO) according to the following equation: 2Mg(s) + O2(g) → 2MgO(s) ... Thus, a reduction half reaction can be written for the O2 as it gains 4 electrons: O2(g) + 4e− → 2O.
What important points do you need to remember about combustion?
Explanation:
A substance burning in the presence of oxygen and leads to the formation of heat and light is called combustion.
Some important points about combustion are as follows:
Fuel should be present for burning.Air should be present for the supply of oxygen.There should be heat (or ignition temperature) to initiate the chemical reaction.Which of the following elements will function as an cathode when it reacts with Mg?
1. Ba
2. Ag
3. Sr
4. K
Answer:
2. Ag
Explanation:
A cathode gains electrons therefore electrons are reduced. Silver (Ag) is a stronger oxidising agent than magnesium.
Please answer quickly!! 20 points!!9. Which represents the greatest mass of chlorine?
A) 1 mole of chlorine
B) 1 atom of chlorine
C) 1 gram of chlorine
D) 1 molecule of chlorine
Answer:
1 mole
Explanation:
if correct you may follow me for more helps
Among the given quantities, the greatest mass of chlorine is represented by one molecule of chlorine Cl₂ that is equal to 71 grams.
What is one molecules?A molecule of an element is formed by the combination of two atoms of that element. One mole of an element is the amount containing 6.022 × 10²³ atoms. This s number is called Avogadro number.
The mass of one mole of an element is called its atomic mass. Cl is 17th element. Atomic mass of Cl = 35.5 g
35.5 g of Cl is called one mole of Cl containing Avogadro number of atoms.
One molecule of Cl is represented as Cl₂ with the mass = 35.5 × 2 = 71 g.
This is the molecular mass of Cl.
One gram of Cl is small amount and mass of one atom of Cl is even smaller. Thus, one molecules of Cl represents the greater mass here. Hence, option D is correct.
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Which substance would you expect to dissolve most rapidly in 100 mL water?
A
0.4 g granulated sugar
B
0.2 g powdered sugar
C
0.4 g powdered sugar
D
0.2 g sugar cube
Answer:
b because it is just 0.2 g and powdered sugar has more contact surface than granulated sugar or sugar cube
The solubility can be given as the amount of solute that can be dissolved in the 100 ml of the solution. The most rapidly dissolved sugar in water is 0.2 gram powdered sugar.
What is a contact surface?The contact surface can be given as the area of the compound that is in direct contact with the solution.
The solubility of the compound is found more in the solute with increased surface area.
The surface area of powdered sugar will be maximum, as more granules of the sugar will be in contact with the water than the cube or the granulated sugar.
Thus, the most rapid dissolution in water is found with 0.2 grams of powdered sugar. Thus, option B is correct.
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This mathematical model describes the changes that occur in a sample of water as its temperature increases. Based on this model, how do you expect the motion of the molecules in ice to compare with the motion of molecules in water vapor?
A. I expect the molecules in ice to move more quickly than the molecules in water vapor.
B. This model does not provide enough data to answer the question.
C. I expect the motion to be very similar.
D. I expect the molecules n water vapor to move more quickly than the molecules in ice.
Answer:
D
Explanation:
the motion of particles can move more quickly due to weak force of attraction. water vapour is a gas hence the answer
You are reacting hydrogen gas with tin oxide to purify tin. SnO2 + 2 H2 → Sn + 2 H2O. You have 45.8L of H2 gas and 351.3g of SnO2. What will be the limiting reactant, and how much of the excess reactant will be left over?
Answer: The limiting reactant is hydrogen gas and the mass of excess reactant [tex](SnO_2)[/tex] left over is 197.43 g
Explanation:
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
......(1)
We are given:
Given mass of [tex]SnO_2[/tex] = 351.3 g
Molar mass of [tex]SnO_2[/tex] = 150.71 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of }SnO_2=\frac{351.3g}{150.71g/mol}=2.33mol[/tex]
At STP conditions:
22.4 L of volume is occupied by 1 mole of a gas
Applying unitary method:
45.8 L of volume will be occupied by = [tex]\frac{1mol}{22.4L}\times 45.8L=2.04mol[/tex] of hydrogen gas
For the given chemical reaction:
[tex]SnO_2+2H_2\rightarrow Sn+2H_2O[/tex]
By stoichiometry of the reaction:
If 2 moles of hydrogen gas reacts with 1 mole of [tex]SnO_2[/tex]
So, 2.04 moles of hydrogen gas will react with = [tex]\frac{1}{2}\times 2.04=1.02mol[/tex] of [tex]SnO_2[/tex]
As the given amount of [tex]SnO_2[/tex] is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.
Thus, hydrogen gas is considered a limiting reagent because it limits the formation of the product.
Moles of excess reactant ([tex]SnO_2[/tex]) left = [2.33 - 1.02] = 1.31 moles
We know, molar mass of [tex]SnO_2[/tex] = 150.71 g/mol
Putting values in equation 1, we get:
[tex]\text{Mass of }SnO_2=(1.31mol\times 150.71g/mol)=197.43g[/tex]
Hence, the limiting reactant is hydrogen gas and the mass of excess reactant [tex](SnO_2)[/tex] left over is 197.43 g
Use the information from the diagram to calculate the enthalpy of combustion for methane. (HELP ASAPPP!!)
A)
+752 kJ
B)
–921 kJ
C)
–604 kJ
D)
+604 kJ
Answer:
where is the diagram sisters
What is the safe way to dispose of a compound containing mercury?
Answer:
Put the items that contains mercury in a zipper top bag and seal the bag. Place the sealed bag in a plastic container with a lid. Pack the container with kitty litter or newspapers to prevent breakage. Make sure the container is labeled “Mercury: Do Not Touch.”
Explanation:
Which of the following weighs least?
a) 0.2g of atoms of N
b) 1 mole of
o 3x10 23 atoms of
d 79 of Ag
Answer:
A
Explanation:
0.2g of atom of nitrogen is the one that weigh least cause of.2g is not up to one mole of nitrogen
Which equation represents positron decay?
Answer: 4
Explanation:
I found it online
How is an endothermic reaction identified?
A. It has a large heat capacity.
B. It gives off heat as a product.
C. It requires heat as a reactant.
O D. It results in a phase change.
Answer:
Endothermic is identified if the process requires heat as a reactant, since endothermic means "intake of heat", so it has to take in some type of heat.
what are alpha particles??
Answer:
a helium nucleus emitted by some radioactive substances, originally regarded as a ray.
Explanation:
Answer:
They're charged particles Identical to the Helium Nucleus
Having 2 protons and 2neutrons and having a Mass of 4.
They're Heavy and slow(speed)In comparison to Beta particles and gamma rays
Usually Emitted from nucleus of radioactive nuclides during decay
How does adding heat energy affect magnesium fluoride (MgF2) molecules?
O A The motion of the molecules decreases.
o
B. The motion of the molecules increases.
O
C. The motion of the molecules is at a constant rate.
D. The motion of the molecules stops.
Answer:
Number B is Answer. The motion of the molecules increases
La solución salina contiene 0.900 gramos de NaCℓ, masa molar = 58.5g / mol, en 100 ml de solución acuosa. La concentración salina, expresada en mol / L, es igual a:
Answer:
0.154 mol/L
Explanation:
Asumamos que tenemos 100 mL de solución, de ser así tendríamos 0.900 g de NaCl. Ahora hay que convertir 0.900 g de NaCl en moles, usando su masa molar:
0.900 g ÷ 58.5 g/mol = 0.0154 molCon el número de moles y el volumen (en litros), se procede a calcular la concentración en mol/L:
100 mL ⇒ 100 / 1000 = 0.100 LConcentración = 0.0154 mol / 0.100 L = 0.154 mol/LPLEASE HELP THIS IS TIMED
Which of the following is a physical change?
CsF(s) + XeFo(s) → CsXeF;(s)
CO2 (s) + CO2(g)
O N2 (g) + 3H2 (g) → 2NH3 (g)
2H2 (g) + O2 (g) → 2H20 (1)
Zn(s) + 2 MnO2(s) + H20(1) → Zn(OH)2(s) + Mn2O3(s)
How did the first plants and animals arrive in Hawaii, before humans?
Where does photosynthesis start?
Answer:
Have a nice day :)
Explanation:
the chloroplast
Photosynthesis occurs in the chloroplast, an organelle specific to plant cells. The light reactions of photosynthesis occur in the thylakoid membranes of the chloroplast. Electron carrier molecules are arranged in electron transport chains that produce ATP and NADPH, which temporarily store chemical energy.
What is the equilibrium expression for the reaction below?
C(s) + O2(9)
2009)
[0][c]
O A.
[CO]
O B.
1
C с
OC.
[co]
[0][c]
CO2]
D.
Answer:
C
Explanation:
because it is product over reactants. hope this helps :)
The equilibrium expression for the reaction C(s) +[tex]O_{2}[/tex](g) ⇄ [tex]CO_{2}[/tex] (g) will be
[[tex]CO_{2}[/tex] ] / [ [tex]O_{2}[/tex] ].
What is equilibrium?Chemical equilibrium is a state where no net change in the quantities of reactants as well as products takes place during a reversible chemical reaction.
The given reaction is C(s) +[tex]O_{2}[/tex](g) ⇄ [tex]CO_{2}[/tex] (g) .
It is known that solid phase is not considered in equilibrium.
Hence, equilibrium expression = [[tex]CO_{2}[/tex] ] / [ [tex]O_{2}[/tex] ].
Therefore, the correct answer will be option (D).
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Find the mass of 3.21 x 10^-2 Nickel
Answer:
1.88 g
Explanation:
n(moles) = mass/molar mass
mass = moles x molar mass of nickel
mass = 3.21x10^-2 x 58.69
mass = 1.883949 grams
mass = 1.88 g (2dp)
Hope this helps :)
Reaction of hypochlorous acid and ammonia is product-favored system at equilibrium. Answer A: Reaction of hypochlorous acid and ammonia is product-favored system at equilibrium. A Reaction of hypochlorous acid and ammonia is reactant-favored system at equilibrium. Answer B: Reaction of hypochlorous acid and ammonia is reactant-favored system at equilibrium. B Reaction of hypochlorous acid and ammonia yields pH 7.00. Answer C: Reaction of hypochlorous acid and ammonia yields pH 7.00. C No reaction occurs between hypochlorous acid and ammonia. Answer D: No reaction occurs between hypochlorous acid and ammonia. D Further data are needed to draw a conclusion about a prospective reaction.
Answer:
A. True
B. False
Explanation:
Reaction between hypochlorous acid and ammonia does not yields a Ph value of 7.00 , this value is defined to water and no other reaction can yield exactly this Ph value. The acid reaction will give a Ph value below 7 while a base reaction will give Ph value of above 7.
Evolution can best be described as
A)
the change in size of body structures through use and disuse
B)
the formation of fossils
C)
a process of growth in an organism
D)
a process of change through time
1. Which of the following combinations correctly represents the process of
photosynthesis?
a) Carbon Dioxide + Water + solar energy - Glucose + Oxygen
b) Carbon Dioxide + Water - Glucose + Oxygen + solar energy
c) Glucose + Oxygen Carbon Dioxide + Water + energy
d) Glucose + Oxygen + energy +
Carbon Dioxide + Water
Answer:
A
Explanation:
Answer:
I think It should be option A. It would have been B but, solar energy is not giving out, it's taken in
A sealed balloon filled with 5.00 liters of gas has a pressure of 1.49 atm. This balloon is taken under water where the pressure of the gas becomes 7.62
atm. What is the new volume of this gas? (Assume the temperature does not change.)
O 56.7L
0 0.978 L
0 1.02 L
O 2.27L
Answer:
0.978L
Explanation:
Using Boyle's law equation as follows;
P1V1 = P2V2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (L)
V2 = final volume (L)
According to the provided information,
P1 = 1.49 atm
V1 = 5.00 liters
P2 = 7.62 atm
V2 = ?
Using P1V1 = P2V2
1.49 × 5 = 7.62 × V2
7.45 = 7.62V2
V2 = 7.45/7.62
V2 = 0.978L
The period of development from fertilized egg to birth is known as
The period of development from fertilized egg to birth is known as [tex]{ \bf{ \underbrace{prenatal\: development}}}[/tex].
[tex]\bold{ \green{ \star{ \orange{Mystique35}}}}⋆[/tex]
Mass x height x gravity is the formula to calculate:
Answer:
Potential energy
Explanation:
[tex]p.e = mgh[/tex]
what is the weight in grams of 1 mole of ammonium sulfate (NH4)2SO4
Answer:
The molar mass of one molecule of ammonium sulfate (NH4)2 SO4 132.14 grams per mole
Answer: 132.15 g
Explanation:
If this question is from a mastery test on Edmentum, I just took it and this was the correct answer
4. A shepherd is increasing his heard from 300 goats to 600 goats. Currently, the land is sufficient to feed 300 goats; what could be the result?
Answer: 300 goats want get food
Explanation:
Ayudaaa. ¿Cuál es el punto de ebullición del agua en grados Celsius?
The question is: Help. What is the boiling point of water in degrees Celsius?
Answer: The boiling point of water in degrees Celsius is [tex]100^{o}C[/tex].
Explanation:
The temperature at which vapor pressure of a liquid becomes equal to the atmospheric pressure is called boiling point.
For example, the boiling point of water is [tex]100^{o}C[/tex].
This means that at [tex]100^{o}C[/tex] the molecules of water are having an equilibrium between liquid and vapor state of theirs.
Thus, we can conclude that the boiling point of water in degrees Celsius is [tex]100^{o}C[/tex].
What does it mean for something to be radioactive?
A. It has an emission spectrum.
B. It is in a stable condition.
C. It generates radio waves.
D. Its nuclei can split apart.
Answer:
D
Explanation:
Radioactivity means
the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei
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Si se hace reaccionar CH3CH3 (etano) con cloro, en presencia de luz ultravioleta, los productos obtenidos en este paso son
Answer:
La reacción de etano, CH₃CH₃ y cloro, Cl₂ en presencia de luz solar se conoce como reacción de halogenación.
Los radicales de cloro se forman cuando el cloro se expone a la luz solar a continuación;
Cl₂ → 2Cl *
Se forma un radical etano cuando el etano, C₂H₆ reacciona con un radical libre de cloro, Cl *, como sigue;
C₂H₆ + Cl → C₂H₅ * + HCl
Se forma un producto halogenado cuando un radical libre de etano reacciona con una molécula de cloro como sigue;
C₂H₅ * + Cl₂ → C₂H₅Cl + Cl *
Un producto halogenado puede reaccionar además con un radical libre para producir como sigue;
C₂H₅Cl + Cl * → C₂H₅Cl₂
Explanation:
