Answer:
total no. of electron present in Valency shell is called valency electron ___________________valency shell is that in which last electron is presentwhen 3.18 g of copper (||) oxide were carefully heated in a stream of dry hydrogen, 2.54 g of copper and 0.72 g of water were formed determine the number of moles of hydrogen atoms which combine with one mole of oxygen atoms
Answer:
the number of moles of atom is 0.91584
Which reverses the flow of current through an electric motor?
A brush
B battery
C armature
D commutator
Answer:
D
Commutator is the answer
Explanation:
The commutator systematically converts the current direction between the rotor and the outer circuit. As the shaft revolves, the commutator converts the course of current in a winding. For a separate armature winding, when a cylinder has reached one-half perfect turn, the winding is now attached so that current passes through it in the reverse of the original direction.
Answer:
D. Commutator
Explanation:
I just took the quiz. credit to the person above me.
Calculate normality and tire of KOH solution , if CN H2 C2 O4 solution , that is nessesary for titration is 0.1050 mol/1 and the Volume is 5.0 ml ; the volume of KOH - solution is 4.5 ml
Answer:
Normality of KOH = 0.1062 N
Note: The given question is not clearly stated. A related question below is answered and explained;
What is the NORMALITY of a solution of KOH if 45.18 mL are required to neutralize 0.3g of pure oxalic acid H2C2O4 . 2H2O?
Explanation:
Equation of the reaction: 2KOH + H₂C₂O₄.2H₂O --> K₂C₂O₄ + 4H₂O
molar mass 0f KOH = 56 g/mol; molar mass of H₂C₂O₄.2H₂O = 126 g/mol
Number of moles of in 0.3 g of H₂C₂O₄.2H₂O = mass/molar mass
number of moles = 0.3 g / 126 g/mol = 0.0024 moles
From the equation of reaction, 2 moles of KOH are required to neutralize 1 mole of H₂C₂O₄.2H₂O
Number of moles of KOH required to neutralize 0.0024 moles of H₂C₂O₄.2H₂O = 2 * 0.0024 = 0.0048 moles
Molar concentration of 45.18 mL solution of KOH containing 0.0048 moles of KOH = number of moles/volume (L)
molarity of KOH solution = (0.0048/45.18 mL) * (1000 mL/1 L) = 0.1062 mol/L
Normality = n * molarity
where is the number of moles of OH⁻ ions produces from mole of KOH = 1
Normality of KOH = 1 * 0.1062
Normality of KOH = 0.1062 N
50 POINTS..!!! NEED RHE ANSWER ASAP..!!! consider the original wave at the top of the illustration. compare the original wave to the other four. which wave represents a wave with the same volume but a lower pitch?
a). wave a
b). wave b
c). wave c
d). wave d
Answer:
my best guess is b
Explanation:
typically the lower the pitch the longer the wave line inbetween the inclines are
Calculate: (5.03 x 109) – (42.6 x 108) =
Answer: x108(5.03x−42.6)
Explanation: Factor 5.03x109−42.6x108
5.03x109−42.6x108
=x108(5.03x−42.6)
if hydrochloride tablets and eno combine what will the reaction
answer is attached in the image below
Answer:
Hydrochloric Acid
Explanation:
A silver ring reacts with compounds containing sulfur in the air to form silver sulfide, a black substance that makes up the tarnish on the surface of silver objects. To remove the tarnish from the ring, students placed it in a pan lined with aluminum foil and added hot water. Baking soda was added to the hot water and stirred. Students made observations about the process. Which observation of this process provides evidence of a chemical reaction?
Question 4 options:
A Hot water heated the aluminum foil.
B The liquid solution changed color.
C The pan was lined with aluminum foil.
D The hot water cooled.
Answer:
c lined with aluminum foil
A template of a Venn diagram representing common and differentiating characteristics of covalent and ionic bonds is shown.
Which of the following characteristics can be written only in space B?
Occurs in substances that have at least one non-metal
Occurs in substances that have a repeating lattice structure
Occurs in substances that have discrete molecular structure
Occurs in substances that have high melting points
Ionic and covalent bonds can occur in substances that have a repeating lattice structure.
Ionic and covalent bondsIonic bonds are formed when an atom donates electron (s) to another atom. Covalent bonds, on the other hand, are formed when two atoms share electrons to complete their octet states.
Ionic compounds are formed from a combination of metal and non-metal atoms. They usually have crystalline lattice structures with high melting points.
Covalent compounds are formed between non-metal atoms. They can also have lattice structures but generally have lower melting points because the forces holding the molecules together are weaker.
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Answer:
Occurs in substances that have a repeating lattice structure
Explanation:
QUICK
Which of these is a ball and stick model?
The model below shows a part of a human body's muscular system.
Muscles are organs that make movement possible. Which organ system is responsible for controlling muscular movement?
A. Endocrine system
B. Skeletal system
C. Nervous system
D. Digestive system
Answer:
you must go to jones im doing the same test
Explanation:
#1 - What is a pure substance? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#2 - TRUE OF FALSE: Water is a pure substance.
1 point
True
False
#3 - What is an atom? *
1 point
the smallest unit of an element that keeps the properties of that element
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#4 - What is a molecule? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#5 - What is a chemical bond? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#6 - TRUE OR FALSE: Molecules are all the same size. *
1 point
True
False
#7 - What is a compound? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#8 - TRUE OR FALSE: Compounds never form in a fixed ratio. *
1 point
True
False
#9 - TRUE OR FALSE: The structure of matter at the atomic and molecular levels is too small to observe directly. *
1 point
True
False
#10 - TRUE OR FALSE: A complex molecule may contain a few atoms bonded together. A simple molecule may contain thousands of atoms. *
1 point
True
False
#11 - What is a crystal? *
1 point
two or more atoms held together by chemical bonds
a substance in which the particles are arranged in an orderly, geometric, and repeating pattern
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#12 - TRUE OR FALSE: Diamond and graphite are both made of carbon atoms. *
1 point
True
False
Answer/Explanation:
#1 - A pure substance is either an element or a compound, making it different from a mixture. A sample of matter that has specific chemical and physical properties is the only one that fits here.
#2 - A pure substance is either an element or a compound, making it different from a mixture. Water is a compound, and thus this would be true.
#3 - An atom is the smallest unit of an element that keeps the properties of that element. Just refer to its definition.
#4 - A molecule is two or more atoms held together by chemical bonds . Again, just refer to its definition.
#5 - A chemical bond is the attractive force that holds atoms together . Jus refer to its definition.
#6 - Molecules are most definitely not all the same size, especially given the huge number of them. This would be false.
#7 - A compound is a pure substance made up of two or more different types of atoms joined by chemical bonds . Just refer to its definition.
#8 - Compounds always form in a fixed ratio, so this would be false.
#9 - If by directly, the problem means with the naked eye, this would be true.
#10 - False. It's reversed.
#11 - A crystal is a substance in which the particles are arranged in an orderly, geometric, and repeating pattern . Just refer to its definition.
#12 -True; to be more specific, they are covalent network solids.
If you put a piece of zinc into a solution of copper (I) sulfate and allow the single replacement reaction to go to completion, how will you know which of the reactants is the limiting reactant? Write the balanced equation, including the states of matter of the reactants and products, to help support your answer.
Explanation:
Reaction of zinc metal in copper sulfate solution.
[tex]\begin{array}{ll}\text { Oxidation : } & \mathrm{Zn}(s) \rightarrow \mathrm{Zn}^{2+}(a q)+2 e^{-}\\\text {Reduction : } & \mathrm{Cu}^{2+}(a q)+2 e^{-} \rightarrow \mathrm{Cu}(s) \\\hline \text { Full Reaction : } & \mathrm{Zn}(s)+\mathrm{Cu}^{2+}(a q) \rightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cu}(s)\end{array}[/tex]
Zinc is listed above copper on the activity series, this means that zinc is more easily oxidized than copper. That is why copper(II) ions can act as an oxidizing agent when put into contact with zinc metal. Ions of any metal that is below zinc, such as lead or silver, would oxidize the zinc in a similar reaction.
The number of waves that pass a given point in a certain amount of
time is the waves...
Answer:
100
Explanation:
nsvcscjkvschssvds
Which diagram shows an element?
Which of the following would be found ONLY in plant cells
Answer:
chloroplasts, cell walls, or intracellular vacuoles
Explanation:
You didn't list the following, but I'm guessing it is chloroplasts, cell walls, or intracellular vacuoles
Which sentence is a scientific statement?
A.
There is a substance around us that cannot be detected.
B.
Kids should go to school for 12 years.
C.
Experimentation is the best way to obtain knowledge.
D.
Unicorns once existed on Earth.
E.
There are no living things on the Moon.
B. Kids should go to school for 12 years.
What is a scientific statement?Scientific statements are those statements that must be falsifiable which means that able to be proven false while on the other hand, tautology is a statement that is true. The sun revolves around the earth” is an example of scientific statement because this statement can be falsifiable in the light of evidences and researches. Hypothesis is a statement that may be true or false. We can verify it by doing experiments.
So we can conclude that option B is the sentence that represents a scientific statement.
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How many grams are in 56 L of chlorine gas?
Answer:
Since 1 L equals to 1000 microlitres, and 1 microlitre equals to 1 gram, there are 56 * 1000 = 56000 grams of chlorine gas in 56 L of chlorine gas.
Explanation:
Hope this helped!
help is science, if you don't know the answer just don't put anything /:
Answer:
Light
Explanation:
Light is a good example of invisible particles. We cannot see light particles aka photon. We only know the light is present by the objects we see. Because we can only see objects when light reflects from them on our eyes.
[I could only think of one example if I can remember one more I'll edit it down]
What is causing the Hot Springs to be so hot? What is causing Hot Springs to be so acidic?
Answer:
Hot springs are hot because of geothermal heat. The Hot springs are acidic because hydrogen sulfide and carbon dioxide get in touch with water they evaporate which causes acid.
Explanation:
(30 points) Ahhhhhhh can someone help me :'))
I'm not smart and I don't understand how to solve this problem:
Octane, one of the major components of gasoline, burns in air according to this unbalanced equation:
C₈H₁₈ (l) + O₂ (g) ----> CO₂ (g) +H₂O
The formula balanced is: 2 C₈H₁₈ (l) + 50 O₂ (g) ----> 16 CO₂ (g) + 18 H₂O
a) What volume of O₂ at STP is needed to burn 702g (1.00L) of octane?
b) What volume of O₂ at 18°C and 0.975 atm is needed to burn 702g of octane?
Answer:
a. 137.93 dm3
b. 150.61 L
Answer:
C₈H₁₈
Explanation:
6.3 moles of water h20
Answer:
6.3 moles of water = 6.3*18=113.4 grams per mole
Explanation:
Why does salt sprinkled on icy roads cause the ice to melt?
Answer:
The actual reason that the application of salt causes ice to melt is that a solution of water and dissolved salt has a lower freezing point than pure water. When added to ice, salt first dissolves in the film of liquid water that is always present on the surface, thereby lowering its freezing point below the ices temperature. Ice in contact with salty water therefore melts, creating more liquid water, which dissolves more salt, thereby causing more ice to melt, and so on.
is methane used as fule
gas true or false
Answer:
its true methane is used as a fuel gas
Explanation:
All matter has both physical and chemical properties.
True or False
Answer:
F
Explanation:
what would you need to do to calculate the molarity of 10g of NaCl in 2kg of water?
A. convert the 10 g of NaCl to Kg of NaCl
B. Convert the 10g of NaCl to moles of NaCl
C. Convert the 2kg of water to liters of water
D. Convert the 2kg of water to moles of water
Answer:
B) we will convert the 10 g of NaCl into moles.
Explanation:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
we will convert the 10 g of NaCl into moles.
Number of moles of NaCl:
Number of moles = mass/molar mass
Number of moles = 10 g/ 58.44 gmol
Number of moles = 0.17 mol
1 Kg = 1 L
Molarity = 0.17 mol / 2 L
Molarity = 0.085 mol/L
Molarity = 0.085 M
Answer:
B. Convert the 10g of NaCl to moles of NaCl
How many grams of NaCl would be required
to react with 346 mL of 0.607 M AgNO3
solution?
Answer:
Mass = 12.27 g
Explanation:
Given data:
Mass of NaCl are required = ?
Volume of AgNO₃ = 346 mL (346 mL× 1L/ 1000 mL = 0.346 L)
Molarity of AgNO₃ = 0.607 M
Solution:
Chemical equation:
NaCl + AgNO₃ → NaNO₃ + AgCl
Number of moles of AgNO₃:
Molarity = number of moles / volume in L
0.607 M = number of moles / 0.346 L
number of moles = 0.607 M × 0.346 L
number of moles = 0.21 mol
now we will compare the moles of NaCl and AgNO₃.
AgNO₃ : NaCl
1 : 1
0.21 : 0.21
Mass of NaCl:
Mass = number of moles × molar mass
Mass = 0.21 mol × 58.44 g/mol
Mass = 12.27 g
HELP
1) A 400g sample of alcohol (c = 2.43 J/g°C) at 16°C is mixed with 400g
of water (c = 4.19 J/g°C) at 85°C. What is the final temperature of the
mixture?
Answer:
Explanation:
Given data:
Mass of alcohol = 400 g
Specific heat capacity of alcohol = 2.43 J/g°C
Initial temperature of alcohol = 16°C
Mass of water = 400 g
Specific heat capacity of water = 4.19 J/g°C
Initial temperature of water = 85°C
Final temperature of mixture = ?
Solution:
Equation:
m₁c₁ (T₂-T₁ ) = m₂c₂(T₂-T₁)
by putting values,
400 × 4.19 × (T₂ - 85°C) = 400 × 2.43 × (T₂ - 16°C)
1676 × (T₂ - 85°C) = 972 × (T₂ - 16°C)
formula of preparation of sodium hydroxide
The chemical formula of sodium hydroxide is NaOH, and its molar mass is 40.01 g/mol. It is the alkali salt of sodium, and its structure is shown below:
It is an ionic compound consisting of sodium cation (Na+) and hydroxide (OH-) anion.
define effervesence
Answer:
is the getting out of a gas in a water solution or it the property of forming bubbles
Evaluate the carbon dioxide molecule. Explain how to determine if double or triple bonds exist in the molecule.
Answer:
It contain double Bond.
Explanation:
To determine weather the bond is double or triple simply check the electron involved in mutual sharing of an electron if 2 electron takes parts it said to be double or if 3 it said to be triple.