Answer:
The identity of unknown substance is Barium.
Explanation:
The given compound has a formula of MCl2. And the percentage of chlorine in this compound is said to be 34.1 %. But, we know that the mass of chlorine in this compound is, 35.5*2 = 71 g
Therefore, if we let x be the total mass of the compound, then:
34.1% of x = 71 g
(0.341)x = 71 g
x = 71 g/0.341
x = 208.2 g
Hence, the mass of other atom M, must be:
M = x - 71 g
M = 208.2 g - 71 g
M = 137.2 g
Now, we look into periodic table in group II. We find that the element is Barium with atomic mass of 137 g.
The identity of unknown substance is Barium.
Barium forms a metal chloride whose percentage of chlorine is 34.1 %. The unknown substance is barium chloride.
We have a Group II metal chloride with a general formula MCl₂. The molar mass of Cl⁻ is 35.45 g/mol. The mass of 2 moles of Cl⁻ is:
[tex]2 mol Cl^{-} \times \frac{35.45g Cl^{-} }{1mol Cl^{-} } = 70.90g Cl^{-}[/tex]
70.90 g represents 34.1% of 1 mole of MCl₂. The molar mass of MCl₂ is:
[tex]70.90gCl^{-} \times \frac{100gMgCl_2}{34.1gCl^{-} } = 208gMgCl_2[/tex]
208 g of MCl₂ contains 70.90 g of Cl⁻. The mass of M²⁺ in 1 mole of MCl₂ is:
[tex]mMCl_2 = mCl^{-} + mM^{2+} \\\\mM^{2+} = mMCl_2 - mCl^{-} = 208g-70.9 g = 137.1 g[/tex]
Barium has a molar mass of 137.3 g/mol, so M must be barium. The unknown substance is barium chloride.
Barium forms a metal chloride whose percentage of chlorine is 34.1 %. The unknown substance is barium chloride.
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Hope is testing a substance using blue litmus paper. The paper turns red. The substance is _____.
a neutral
an acid
a base
Answer:
the substance is an acid
How could the continents have gotten so far apart and how long did it take for this to happen
What is the energy of a photon of red light having a frequency of 3.08 x 10^14 HZ?
Answer:
2.04 x 10⁻¹⁹J
Explanation:
Given parameters:
Frequency = 3.08 x 10¹⁴Hz
Unknown:
The energy of the photon = ?
Solution:
The energy of a photon is given as;
E = hf
Where h is the planck's constant
f is the frequency
Insert the parameters and solve;
E = 6.63 x 10⁻³⁴ x 3.08 x 10¹⁴
E = 20.4 x 10⁻³⁴⁺¹⁴
E = 20.4 x 10⁻²⁰ = 2.04 x 10⁻¹⁹J
Answer:
2.97*10-19 j
Explanation:
E=Energy of photon
H=Planck constant=6.626*10-34
V=Frequency of photon
we can plug what we already know E=(6.626*10-34)(4.48*10 14)
Which molecule would have this shape?
Answer:
CO2
Explanation:
the subscript tells you how many of one element is used for this case there is one black atom and 2 red ones so you only need 1 carbon and 2 oxygens.
hope this helps. brainliest please?
A reaction where heat is added is a(n)
endothermic reaction
heterogeneous reaction
reversible reaction
in endothermic reaction heat is added
What is the mass of 6.2x 1022 molecules of carbon monoxide?
Answer:
Mass = 2.8 g
Explanation:
Given data:
Number of molecules of CO = 6.2×10²²
Mass of CO = ?
Solution:
We will use Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
For given 6.2×10²² molecules of CO mass will be,
1 mole = 6.022 × 10²³ molecules of CO
6.2×10²² molecule × 1 mole/ 6.022 × 10²³ molecules of CO
0.1 mol
Mass of CO:
Mass = number of moles × molar mass
Mass = 0.1 mol × 28 g/mol
Mass = 2.8 g
Which pair has the stronger ionic bond:
- MgCl2 vs. NaCl2
- NaCl vs. LiCl
Marcy tests a solution with a strip of blue litmus paper. The paper turns red. The solution is _____.
acidic
basic
neutral
Suppose you mix Na2SO4 and KCl solutions according to the given equation.
Na2SO4 (aq) + 2 KCl(aq) + 2 NaCl(aq) + K2SO4 (aq)
What evidence of a reaction do you expect to see?
Select one:
A precipitate should form.
A gas should form.
Water should form.
Ο Ο
No reaction should occur.
Answer:
No reaction should occur
Explanation:
Water cannnot be made from the components
Nothing will be released as a gas
Both products are soluible in water therefore will not form a precipitate.
If I mix a solution of Na2SO4 and KCl, no reaction should occur.
Whether or not, a reaction occurs when two substances are mixed depends on the respective positions of the substances in the electrochemical series.
Now, we are expecting the reaction; Na2SO4 (aq) + 2 KCl(aq) + 2 NaCl(aq) + K2SO4 (aq) to occur. The big question is, between sodium and potassium, which is higher in the electrochemical series?
A little look into the image attached shows that potassium is higher than sodium in the series so the reaction is possible.
However, the both products are aqueous, they are both soluble in water hence no visible reaction occurs.
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Ionic crystals have high boiling points because:
A. They do not have high boiling points.
B. breaking ionic bonds requires a large amount of energy.
C. the structure has a large surface area to absorb heat quickly.
D. the positive and negative charges prevent them from absorbing heat quickly.
The answer would be B.
Cold-winter survival experts do not recommend eating snow for hydration. One reason for this is the energy it takes to increase temperature of the snow, melt it, and then increase the temperature of the resulting water to body temperature. Calculate the total amount of heat to convert 2.000 kg of snow at -15.00 0C to liquid water at 38.00 0C.
POTENTIALLY HELPFUL INFORMATION:
The heat of fusion for water is 1.44 kcal/mol.
The specific heat capacity of solid water is 0.488 cal/g0C.
The specific heat capacity of liquid water is 1.00 cal/g0C.
The freezing point of water is 00C (also known as melting point).
Answer:
The total amount of heat is 250.64 kcal.
Explanation:
Given that,
Total amount of heat = 2.000 kg
Temperature of snow = -15.00°C
Temperature of water = 38.00°C
Heat of fusion of water = 1.44 kcal/mol
Specific heat of solid water = 0.488 cal/g°C
Specific heat of liquid = 1.00 cal/g°C
We need to calculate the heat required to bring temperature -15°C to 0°C snow
Using formula of heat
[tex]Q_{1}=mc_{p}\Delta T[/tex]
Put the value into the formula
[tex]Q_{1}=2000\times0.488\times(0+15)[/tex]
[tex]Q_{1}=14640\ cal[/tex]
[tex]Q_{1}=14.640\ kcal[/tex]
We need to calculate the heat required to convert 0°C snow into 0°C water
Using formula of heat
[tex]Q_{2}=ml[/tex]
Put the value into the formula
[tex]Q_{2}=\dfrac{2000}{18}\times1.44[/tex]
[tex]Q_{2}=160\ kcal[/tex]
We need to calculate heat required to increases temperature of water from 0°C to 38°C
Using formula of heat
[tex]Q_{3}=mc_{p}\Delta T[/tex]
Put the value into the formula
[tex]Q_{3}=2000\times1.00\times(38-0)[/tex]
[tex]Q_{3}=76000\ cal[/tex]
[tex]Q_{3}=76\ kcal[/tex]
We need to calculate the total heat
Using all heat amount
[tex]Q=Q_{1}+Q_{2}+Q_{3}[/tex]
Put the value into the formula
[tex]Q=14.640+160+76[/tex]
[tex]Q=250.64\ kcal[/tex]
Hence, The total amount of heat is 250.64 kcal.
7. Which of the following units would be MOST appropriate for measuring
the volume of a small can of soda? *
1 point
A. Liters
B. Milliliters
C. Grams
D. Kilograms
Use the metric ruler to answer questions 8 and 9.
Answer:
im pretty sure the answer is b
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HOPE IT HELPS
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A compound has the following composition by mass:
32% carbon, 6.7% hydrogen, 42.6% oxygen and 18.7% nitrogen
What is the empirical formula of the compound?
Answer:
i cry when im alone
Explanation:
What is the density if the mass is 25 g and the volume is 114 mL?
Answer:
0.219 g/mL.
Explanation:
From the question given above, the following data were obtained:
Mass = 25 g
Volume = 114 mL
Density =.....?
Density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically, it is expressed as:
Density = mass /volume
With the above formula, we can obtain the density of the substance given in the question above as follow:
Mass = 25 g
Volume = 114 mL
Density =.....?
Density = mass /volume
Density = 25/114
Density = 0.219 g/mL
Therefore, the density of the substance is 0.219 g/mL
what istope of an atom if it has 29 protons and 36 neutrons?
Answer:
Copper Atoms
Explanation:
All copper atoms have atomic number 29: all their nuclei contain 29 protons. But they also contain uncharged particles called neutrons. In natural copper, the atoms are of two kinds. One has 29 protons and 34 neutrons in the nucleus; the other has 29 protons and 36 neutrons
after felix adds salt to the boiling water what will he have in the pot
Answer:
Salty water
Explanation:
Sorry for wasting your time.
Plzzzzz help me answer this question (WILL AWARD BRAINLIEST)
what is one beneift of using scientific notation instead of regular notation
Answer:
its shorter than a regular one
Explanation:
the only reason is simply because it is shorter
Forecasting the weather for a specific area is relatively easy because of all the technology that is available.
A. True
B. False
Answer:
A
Explanation:
Which of the following identifies the type of radiation that scientists most likely observed?
Radio
Infrared
Ultraviolet
Gamma Rays
Answer:gamma rays
Explanation:
what is the difference between luster and dull
Luster means Shiny. Dull means simple and not full of detail. Hope this helps!Please Rate Brainiest!
-Aslina
PLEASE HELP!!!!!
What happens to the transfer of thermal energy when thermal equilibrium is reached?
Answer:
During the process of reaching thermal equilibrium heat is transferred between the object. heat is always transferred from the object at the higher temperature to the object with lower temperature. For a gas, the heat transfer is related to a change in temperature.
How many valence electrons would be used in drawing the Lewis Structure CF4?
Answer:
32
Explanation:
You have 7 valance electrons in fluorine, and you have 4 of them. 7*4=28. Then, you have 4 valance electrons on carbon. So 28+4=32
A scientist is studying two types of worms. Worm X has DNA identical to its parent. Worm Y has a combination of DNA from two parents. The scientist determines that one of the worms has a survival advantage over the other worm. Which statement correctly summarizes this conclusion? Worm X reproduces asexually, which gives it genetic variation. Worm Y reproduces sexually, which gives it genetic variation. Worm Y reproduces asexually, which gives it more DNA. Worm X reproduces sexually, which gives it more DNA.
Answer:
2. Worm Y reproduces sexually, which gives it genetic variation.
Answer:
B Worm Y reproduces sexually, which gives it genetic variation.
Explanation:
hope you all have a good day
Electro magnetic waves are blank waves
What’s the blank PLEASE HELP DUE IN 25 MINUTES!!!!
Answer:
Electromagnetic waves or EM waves are waves that are created as a result of vibrations between an electric field and a magnetic field. Hope it helps ;)
The diagram shows a balloon that was rubbed with a piece of cloth what is the change
Answer: the electric charge
Explanation:
The table lists some compounds found in foods and their formulas.
Based on this information, which of these statements is NOT true?
CLEAR
Answer:
A
Explanation:
the number of molecule won't be twice as fructose has 12 hydrogen molecules and lactose has 22 hydrogen molecules
From the given statements, the statement saying that the number of atoms in Lactose is twice the number of atoms in Fructose is not correct. Thus option A is correct.
The given molecules in the list are Glutamine, Lactose, fructose, and Sorbitol.
The number of atoms in the following compounds is:
Glutamine = 20 atomsLactose = 45 atomsFructose = 24 atomsSorbitol = 26 atoms.Statement A says that the number of atoms in Lactose is twice the number of atoms in Fructose. The twice atoms of Fructose are 48 atoms. The number of atoms of lactose is 45.
Thus statement A is incorrect. Thus option A is correct.
For more about the atoms in a molecule, refer to the link:
https://brainly.com/question/25617532
How do changes in population size relate to environmental conditions?
Answer:
No simple relationship exists between population size and environmental change. However, as global population continues to grow, limits on such global resources as arable land, potable water, forests, and fisheries have come into sharper focus.
Explanation:
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Answer:
what are the options?
Explanation:
How can the total energy of an open system be changed? Enter your answer in the space provided.
yes they can be changed becasue they are expose to the environment
That's why it's improtant to have a calorimeter so the energy and heat are contained
The total energy of an open system be changed if:
There is an exchange between matter and energyAccording to the First Law of Thermodynamics, energy cannot be created or destroyed, it can only change form.
An open system is a system that has an interaction with its environment where matter or energy can be added or removed from the environment.
As a result of this, the total energy of an open system can be changed if there is an exchange between matter and energy and they remain constant.
Therefore, the correct answer is an exchange has to take place for the total energy in an open system to be changed.
Read more here:
https://brainly.com/question/20319024