A student determines the calcium content of a solution by first precipitating it as calcium hydroxide, and then decomposing the hydroxide to calcium oxide by heating. How many grams of calcium oxide should the student obtain if his solution contains 55.0 mL of 0.458 M calcium nitrate?
Answer:
1.41g
Explanation:
all work is shown in the attached image :-)
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C. Yes, if each sample contains 6.02 x 10²³ atoms.
Suggest two reasons why carbon dioxide emissions from electricity production decreased from 2012 to 2015
Answer:
global warming
Explanation:
Applying smart electric grid technologies can potentially reduce CO2 emissions.
an organic compound on analysis yielded 2.04g carbon, 0.34g hydrogen, 2.73g oxygen. calculate the empirical formula
Answer:
CH2O
Explanation:
According to this question:
C = 2.04g
H = 0.34g
O = 2.73g
First, we divide the mass value of each element by its atomic mass to convert to moles.
C = 2.04g ÷ 12 = 0.17mol
H = 0.34g ÷ 1 = 0.34mol
O = 2.73g ÷ 16 = 0.17mol
Next, we divide by the smallest mole value (0.17):
C = 0.17mol = 0.17 = 1
H = 0.34mol ÷ 0.17 = 2
O = 0.17mol ÷ 0.17 = 1
The whole number ratio of C,H,O is 1:2:1, hence, the empirical formula is CH2O.
Which of the following numbers is equal to the value snow
notation below?
4.8 x 10^-4
A. 0.0048
ОО
B. 0.00048
C. 0.048
D. 0.000048
Answer:
B
Explanation:
4.8×10^-4
10^-4 = 0.0001
4.8×0.0001 = 0.00048
(b) Which of the following is a mixture?
A.Sodium chloride solution
B.Sodium chloride
C.Sodium
D.Chlorine
Answer:
a
Explanation:
Mixture is a combination of two or more elements and sodium is an element with a chemical symbol Na and a charge of +1 and chloride too is an element with a chemical symbol Cl and a charge of -1 so when these two elements are combine it form a chemical solution called Sodium chloride
Will Mark Brainlest ( all the disaster are hazard but all the hazard are not disaster) give reason
Answer:
Explanation to the following question is as follows;
Explanation:
Any phenomenon that would have the potential to cause severe death or property damage is considered a danger. When the potential for devastation is realised, a hazard becomes a disaster. All catastrophes are risks, but not all risks are catastrophes. Hazards do not always result in devastation.
Answer:
I hope this will help you.
The elements beryllium, calcium, and strontium are all in group 2. What is the correct relationship of these elements regarding their ionization energy?
Answer: The correct relationship of these elements regarding their ionization energy is Strontium < Calcium < Beryllium.
Explanation:
The amount of energy required to remove the most loosely bound electron in an atom is called ionization energy.
Larger is the size of an atom, more easily it can lose an electron. Since the size of atoms increases on moving down in a periodic table so ionization energy decreases down the group.
For example, beryllium, calcium, and strontium are elements of group 2. Strontium is the largest in size and beryllium is the smallest in size.
Hence, the ionization energy of group 2 elements in the increasing order is as follows.
Strontium < Calcium < Beryllium
Thus, we can conclude that the correct relationship of these elements regarding their ionization energy is Strontium < Calcium < Beryllium.
The nonmetals include which of the following groups? Use the periodic table to answer the question. Check all that apply.
halogens
alkali metals
lanthanides
noble gases
alkaline earth metals
Answer:
En el grupo de los no metales se incluyen los halógenos (flúor, cloro, bromo, yodo, astato y téneso), que tienen 7 electrones en su última capa de valencia y los gases nobles (helio, neón, argón, kriptón, xenón, radón), que tienen 8 electrones en su última capa (excepto el helio, que tiene 2).
Explanation:
halógenos
Answer:
1,4
Explanation:
Below are descriptions of different center voids of a solid fuel. Which design
shape will generate the most thrust?
A. A heart
OB. A circle
C. A triangle
O D. A tree with branches
B. A circle.
The center void shape that generates the most thrust in a solid fuel rocket is a circle.
What is Fuel?
Fuel is a substance that is used to produce heat or energy through combustion or other chemical reactions. It can be in the form of a solid, liquid, or gas and is typically used to power engines, generators, or heating systems. Examples of fuels include gasoline, diesel, natural gas, coal, wood, and propane. The choice of fuel depends on factors such as availability, cost, energy content, and environmental impact.
This is because a circular shape allows for the most efficient burning of the fuel, with the flame front moving evenly in all directions. Other shapes, such as a heart, triangle, or tree with branches, can cause uneven burning and may result in less thrust.
Learn more about Fuel from the given link
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Answer:
Explanation:
D.
tree with branches
What is the percent yield of either if 1.11L(d=0.7134 g/mL) is isolated from the reaction of 1.500L of C2H5OH
Answer:
Percent yield of ether = 83.18%
Explanation:
Equation of the synthesis reaction of ether from ethanol is given as follows :
2 C₂H₅OH -----> C₂H₅OC₂H₅ + H₂0
Density = mass / volume
Therefore mass = density × volume
Density of ether = 0.7134 g/mL; volume of ether produced = 1.11 L = 1110 mL; Molar mass of ether = 74 g/mol
Mass of ether produced = 0.7134 g/mL × 1110 mL = 791.874 g
Density of ethanol = 0.789 g/mL; volume of ethanol = 1.50 L = 1500 mL; molar mass of ethanol = 46 g/mol
Mass of ethanol reacted = 0.789 g/mL × 1500 mL = 1183.5 g
From the equation of reaction, 2 mole of ethanol produces 1 mole of ether
Mass of 2 moles of ethanol = 2 × 46 = 92 g
Therefore, 92 g of ethanol produces 74 g of ether
1183.5 g of ethanol will produce 1183.5 × 74/92 grams of ether = 951.945 g of ether
Percent yield of ether = actual yield/theoretical yield × 100%
Actual yield of ether = 791.874 g; theoretical yield of ether = 951.945 g
Percent yield of ether = (791.874 g × 951.945 g) × 100 %
Percent yield of ether = 83.18%
What is the net ionic equation for the following? :)
1. Mg (s) + Na2CrO4 (aq) -->
2. K (s) + Cd(NO3)2 (aq) -->
Answer:
1. Mg (s) + 2Na+(aq) → 2Na(s) + Mg²⁺(aq)
2. 2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)
Explanation:
The net ionic equation of a reaction express only the chemical species that are involved in the reaction:
1. Mg (s) + Na2CrO4 (aq) → 2Na + MgCrO4(aq)
The ionic equation:
Mg (s) + 2Na+(aq) + CrO4²⁻ (aq) → 2Na + Mg²⁺ + CrO4²⁻(aq)
Subtracting the ions that don't change:
Mg (s) + 2Na+(aq) → 2Na + Mg²⁺
2. 2K(s) + Cd(NO3)2(aq) → 2KNO3(aq) + Cd(s)
The ionic equation:
2K(s) + Cd²⁺(aq) + 2NO3⁻(aq) → 2K⁺(aq) + 2NO3⁻(aq) + Cd(s)
Subtracting the ions that don't change:
2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)can someone help me?
Answer:
1: because phosphate contain oxide ions so that is base character
3. According to the Arrhenius theory, which list of compounds includes only acids?
A) HF, H2CO3, and HNO3
B) LiOH, HNO3, and CH3OH
C) H2PO4, HCO3, and NH4Cl
D) HNO3, H2SO4, and C6H12O6
Answer:
C) H2PO4, HCO3, NH4Cl
Explanation:
Because all of the above compounds on reaction with water liberate H+ ion which is the identification of an acid acc to Arhenius Theory
Which statement is not true about the periodic table?
A. Elements in the same family have the same number of protons.
B. An element of the table is represented by a box with a symbol in it.
C. Elements in the same period of the periodic table have the same
number of electron shells.
D. It is organized by atomic number.
Elements in the same family have the same number of protons. This statement is not true about the periodic table. Therefore, option A is correct.
What is periodic table ?The chemical elements are arranged in rows and columns in the periodic table, sometimes referred to as the periodic table of the elements. It is frequently used in physics, chemistry, and other sciences and is frequently regarded as a symbol of chemistry.
The table can be used by scientists to anticipate chemical reactions, study trends in the periodic properties of certain elements, and speculate on the properties of yet-to-be-discovered elements. The elements are arranged in the contemporary periodic table according to their atomic numbers and periodic characteristics.
The periodic table has changed to represent more than 150 years of chemical and physics research and development.
Thus, option A is correct.
To learn more about the periodic table, follow the link;
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In many halocarbons, among them chloroethane (CH3CH2Cl), a halogen is attached to an aliphatic carbon chain. These halocarbons are called _____.
1.carboxylic acids
2.alkyl halides
3.aryl halides
4.phenyl halides
The electrolysis of water forms H2 and O2. 2H2O Right arrow. 2H2 O2 What is the percent yield of O2 if 10.2 g of O2 is produced from the decomposition of 17.0 g of H2O
Answer:
67.5%
Explanation:
Step 1: Write the balanced equation for the electrolysis of water
2 H₂O ⇒ 2 H₂ + O₂
Step 2: Calculate the theoretical yield of O₂ from 17.0 g of H₂O
According to the balanced equation, the mass ratio of H₂O to O₂ is 36.04:32.00.
17.0 g H₂O × 32.00 g O₂/36.04 g H₂O = 15.1 g O₂
Step 3: Calculate the percent yield of O₂
Given the experimental yield of O₂ is 10.2 g, we can calculate its percent yield using the following expression.
%yield = (exp yield / theoret yield) × 100%
%yield = (10.2 g / 15.1 g) × 100% = 67.5%
The bottle slides down the hill and is moving at a velocity of 14 meters/second the instant it hits the ground. The vertical height from where Jeff dropped the bottle is meters. Ignore friction, and use , PE = m × g × h, and g = 9.8 m/s2.
Answer:
10 m
Explanation:
From the question given above, the following data were obtained:
Velocity (v) = 14 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
Next, we shall determine the energy. This can be obtained as follow:
Velocity (v) = 14 m/s
Kinetic Energy (KE) =?
KE = ½mv²
KE = ½ × m × 14²
KE = ½ × m × 196
KE = m × 98
Finally, we shall determine the height. This can be obtained as follow:
Kinetic energy (KE) = m × 98
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
Since the object is falling from a particular height,
Potential energy (PE) = kinetic energy (KE)
PE = mgh
KE = m × 98
m × 9.8 × h = m × 98
Divide both side by m × 9.8
h = m × 98 / m × 9.8
h = 10 m
Thus, the bottle was dropped from a height of 10 m
Which is a possible consequence of decreasing air quality resulting from global warming? drying out of fertile lands flooding of low-lying coastal areas melting of glaciers and polar ice caps decrease in population due to health threats The correct answer is decrease in population due to health threats.
Answer: A decrease in population due to health threats is a possible consequence of decreasing air quality resulting from global warming.
Explanation:
When average temperature of Earth keeps on increasing for a longer period of time due to greenhouse gases, increased level of carbon dioxide and other gases etc then it is called global warming.
As humans use oxygen to sustain which is present in the air. So, when there will occur decrease in air quality that results from global warming then it means more illness or diseases will be there.
Hence, people will tend to die more often because of decrease in the air quality their health is getting affected.
Thus, we can conclude that a decrease in population due to health threats is a possible consequence of decreasing air quality resulting from global warming.
Answer:
A decrease in population due to health threats is a possible consequence of decreasing air quality resulting from global warming.
Explanation:
Hope this helps.
cuantas moléculas de oxigeno se producen por la descomposición de 28.5 g de H2O2 (masa molecular = 34.0g/mol) de acuerdo a la ecuación
2H2O2(l) → 2H2O(l)+O2(g)
The question is as follows: How many oxygen molecules are produced by the decomposition of 28.5 g of H2O2 (molecular mass = 34.0g / mol) according to the equation
2H2O2 (l) → 2H2O (l) + O2 (g)
Answer: There are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].
Explanation:
Given: Mass of [tex]H_{2}O_{2}[/tex] = 28.5 g
As moles is the mass of a substance divided by its molar mass. Hence, moles of [tex]H_{2}O_{2}[/tex] is calculated as follow.
[tex]Moles = \frac{mass}{molarmass}\\= \frac{28.5 g}{34.0 g/mol}\\= 0.838 mol[/tex]
According to the given equation, 2 moles of [tex]H_{2}O_{2}[/tex] gives 1 mole of [tex]O_{2}[/tex]. So, moles of [tex]O_{2}[/tex] produced by 0.838 moles of [tex]H_{2}O_{2}[/tex] will be calculated as follows.
[tex]Moles of O_{2} = \frac{0.838 mol}{2}\\= 0.419 mol[/tex]
This means that moles of [tex]O_{2}[/tex] produced is 0.419 mol.
As per the mole concept, 1 mole of every substance has [tex]6.022 \times 10^{23}[/tex] molecules.
So, molecules of [tex]O_{2}[/tex] present in 0.419 mole are as follows.
[tex]0.419 \times 6.022 \times 10^{23}\\= 2.52 \times 10^{23}[/tex]
Thus, we can conclude that there are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].
3. Which of the following is a property of a metal?
A. brittle
B. bendable
C. poor conductor of heat and electricity
D. usually dull in appearance
Answer:
the answer would be d. usually dull in appearance
Explanation:
because brittle bendable and poor conductor of heat and electricity are all for the non-metals
Answer:
C !!
Explanation:
hope this helps! usually people classify metals based on if they can conduct heat or electricity
What is the weight on Earth of an apple with mass 150g?
name a food that contain an acid
Answer:
name a food that contain an acid
1. nuts
2. dairy
3. grains
3. meat
these are the foods which contains acids.
hope its helps you
have a great day keep smiling be happy stay safe.
In the periodic table, identify the element X on its average atomic mass
Answer:
Potassium
Explanation:
To solve this question we need to find, as first, the average atomic mass of the element knowing that is defined as the sum of the masses of each isotope times their abundances. For the element X:
Average atomic mass:
38*0.0967 + 39*0.7868 + 40*0.1134 + 41*0.0031
= 39.02g/mol
The atom that has the average atomic mass closest to 39.02g/mol is Potassium, K = 39.10g/mol.
write a short note on detection of nitrogen in the organic compound
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Describe the energy in natural gas and the way in which it’s converted to electrical energy.
what are neutral salts
Answer:
Salts that produce acidic solutions are acid salts. Neutral salts are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered to be salts. Examples of zwitterions include amino acids, many metabolites, peptides, and proteins.
Explanation:
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.
For class 10th
Answer:
Water contains two parts of hydrogen and one part oxygen. Therefore, during the electrolysis of water the amount of hydrogen has collected in one of the test tubes is double than that of the oxygen produced and collected in the other last tube.
What is the most important criteria for using chromatography to separate components from a mixture
Answer:
this is your answer i hope it will help you if this answer is right then folow meChromatography can be quantitatively found by the retention factor. Therefore, the important criterion to use chromatography for separating components of a mixture is the difference in solubility of the liquids.
A UV wave has a smaller___
than visible light.
Answer:
wavelength
Explanation:
