Answer:
volume = 15.568dm³
Explanation:
n = mass/molar mass
n = 26.4/38
n = 0.675mole
0.695 = volume/22.4dm³
volume = 15.568dm³
What is the percentage of OH- in Ca(OH)2
By weight the hydroxides are 45.9% of the weight
The mass percentage of the OH⁻ in the compound Ca(OH)₂ is 45.94 %.
What is the mass percentage?The percentage of any element or group of atoms in a given compound is the number of parts by mass of that element or group of atoms present in 100 parts by mass of the given compound.
The percentage of an element can be calculated in 2 steps:
First, calculate the molar mass of the compound by the addition of the atomic masses of the atoms. Then, the percentage of the elements by dividing the total mass of the element or or group of atoms by the molar mass of the compound multiplied by 100.
Given, the molecular formula of the given compound is Ca(OH)₂. The atomic mass of calcium, hydrogen, and oxygen is 40g, 1 g, and 16 respectively.
The molecular mass of the Ca(OH)₂ = 74 g/mol
The mass of OH in Ca(OH)₂ = 34 g
The mass percentage of the OH⁻ = (34/74) × 100 = 45.94 %
Therefore, the mass percentage of the OH in Ca(OH)₂ is equal to 45.94%.
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Which two materials form igneous rocks upon cooling?
A. lava and crystals
B. magma and lava
C.crystals and intrusive rocks
D.intrusive rocks and sediment from rocks
Answer:
B. Magma and Lava
hopefully this helped :3
Answer:
B: magma and lava
Explanation:
10g of sugar is dissolved by water to make 200g of solution of sugar. What is the percent by mass of the solution?
Explanation:
In sugar solution 200 g has sugar 10 g
In sugar solution 100 g has sugar 10/200 × 100
= 5 %w/w
An aluminum kettle weights 1.05 kg and has a heat capacity of 0.9211 J over grams Celsius how much heat is required to increase the temperature of the scuttle from 23.0 Celsius to 90
Answer:
64799.4 J
Explanation:
The following data were obtained from the question:
Mass (M) = 1.05 kg = 1.05 x 1000 = 1050g
Specific heat capacity (C) = 0.9211 J/g°C
Initial temperature (T1) = 23°C
Final temperature (T2) = 90°C
Change in temperature (ΔT) = T2 – T1 =
90°C – 23°C = 67°C
Heat required (Q) =....?
The heat required to increase the temperature of the kettle can b obtain as follow:
Q = MCΔT
Q = 1050 x 0.9211 x 67
Q = 64799.4 J
Therefore, 64799.4 J of heat is required to increase th temperature of the kettle from 23°C to 90°C.
PLEASE HELP!! thank you Which element does X represent?
Answer:
95 Kr36
Explanation:
The process by which a large nucleus split into two smaller nuclei is called nuclear fission and occurs after the nucleus has absorbed a neutron that is a product of the radioactive decay of another atom. The formed fission fragments are unstable and extremely radioactive.
Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices provided. (1) Nonbonding electron pairs are present on the F in the molecule HF. (2) The two atoms involved in a multiple covalent bond must always be atoms of the same element. (3) A molecule of hydrogen peroxide contains the same number of atoms as a molecule of sulfur trioxide does. Group of answer choices All three statements are true. None of the statements are true. Only one of the statements is true. Two of the three statements are true.
Answer:
(1) Nonbonding electron pairs are present on the F in the molecule HF. True
(2) The two atoms involved in a multiple covalent bond must always be atoms of the same element. False
(3) A molecule of hydrogen peroxide contains the same number of atoms as a molecule of sulfur trioxide does. True
Two of the three statements are true.
Explanation:
Non bonding electrons are also known as lone pairs. They are electron pairs present on an atom but are not involved in chemical bonding. They are usually localized on the atom of one of the bonding elements. In HF, there are three nonbonding electrons localized on the fluorine atom that do not participate in chemical bonding.
When multiple bonds are formed between atoms, they must not be atoms of the same element, for instance carbon and nitrogen forms multiple covalent bonds in chemical moieties such as they cyanide ion.
A molecule of hydrogen peroxide (H2O2) contains four atoms just as a molecule of sulphur trioxide(SO3) does.
The breaking down and changing of rocks at or near Earth's surface is called _____.
Answer: Weathering
Explanation:
Weathering can break down rocks and change it shapes.
endothermic or exothermic?
The reaction between ammonium nitrate and water absorbs heat from the surrounding environment.
Three drops of concentrated sulfuric acid added to 100 milliliters of water in a beaker makes the beaker hot.
Ammonium chloride dissolved in a beaker of water makes the beaker cold.
Uranium atoms are split to produce nuclear energy.
Water separates into hydrogen and oxygen when an electric current is run through it.
Methane and oxygen are combined to produce methanol and heat.
Answer:
Endothermic
Exothermic
Endothermic
Exothermic
Exothermic
Exothermic
Explanation:
Endothermic is when a reaction absorbs heat.
Exothermic is when a reaction releases heat.
Endothermic reactions:
The reaction between
ammonium nitrate and
water absorbs heat
from the surrounding
environment.
Ammonium chloride dissolved
in a beaker of water makes the
beaker cold.
Water separates into
hydrogen and oxygen
when an electric current
is run through it.
Exothermic reactions:
Three drops of concentrated
sulfuric acid added to 100
milliliters of water in a beaker
makes the beaker hot.
Uranium atoms are split to
produce nuclear energy.
Methane and oxygen are
combined to produce
methanol and heat.
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For Group 2A metals, which electron is the most difficult to remove? the second the first the third All the electrons are equally difficult to remove.
Answer:
the third
Explanation:
when you remove the first the nucleur attraction becomes greater pulling the other valence electron closer thus the more you remove the harder it gets because the pull from the nucleus increases.
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option C is correct option.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
The elements that belongs to Group 2A metals are alkaline earth metals, their electronic configurations is [noble gas ]ns² so, it is easy to remove first electron and then second electron but it is very difficult to remove the third electron because after removing two electron we get noble gas configuration and effective nuclear charge also increases after removal of second electron.
Therefore, the correct option is option C.
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Use the pictures shown to identify three ways of drawing hydrocarbon molecules.
Then write the molecular formulas. (1 point each)
Answer:
The three ways to in which the hydrocarbons are represented are;
a. The ball and stick model
b. Condensed structural formula
c. Skeletal structure
The molecular formula are
a. C₇H₁₆
b. C₆H₁₄
c. C₅H₁₂
Explanation:
a. The ball and stick model of organic compounds, displays the atoms and bonds in three dimensions, representing the atoms by spares and the bonds by rods
b. The condensed structural formula are similar to the structural formula with the difference that the formula is written in a linear fashion which conserves space and increases ease of writing and are written out faster.
c. In the skeletal structure diagram, the atoms are of the organic compound are combined together in the structural drawing of the essential features of the organic compound. In essence, a skeletal structure, depicts the skeleton of a compound as it is made up of the molecule's skeletal atoms.
The three ways in which the hydrocarbons are represented are:
a. The ball and stick model
b. Condensed structure
c. Skeletal structure
The molecular formula are
a. C₇H₁₆
b. C₆H₁₄
c. C₅H₁₂
Let us understand these models and forms one by one:
a. The ball and stick model of organic compounds, displays the atoms and bonds in three dimensions, representing the atoms by spares and the bonds by rods.
b. The condensed structural formula are similar to the structural formula with the difference that the formula is written in a linear fashion which conserves space and increases ease of writing and are written out faster.
c. In the skeletal structure diagram, the atoms are of the organic compound are combined together in the structural drawing of the essential features of the organic compound. In a skeletal structure, depicts the skeleton of a compound as it is made up of the molecule's skeletal atoms.
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How might a scientist confirm the results of other expirements by doing an experiment
Find the area of a circle inscribed in an equilateral triangle of side 18 cm. ( Take pi= 3.14). answer should be 54.78 cm²
Answer:
The answer according to me.............
Explanation:
Which factor plays the biggest role in delaying the detection of childhood
diseases?
Answer:
poor access to health care providers
Explanation:
without health care providers you cant get tested.
what is photosynthesis?
Answer:production of glucose in the presence of light and chlorophyll from carbondioxide and water
Explanation:
3 point different between fundamental units and derived units
Answer:
Fundamental Units:
1) Fundamental units also called base units are used to describe base quantities
2) They cannot be expressed in terms of derived units.
3) Examples : Meter, Ampere, Second etc.
Derived Units:
1) Derived units are used to describe derived quantities.
2) They can be expressed in terms of fundamental units.
3) Examples: Newton, Joule, Hertz, Pascal etc.
Answer:
3diferences
Explanation:
fundamental are independent but derived are dependent
there are 7fundamental units but there are many derived units from fundamental.
meter, second, kilogram, etc are examples of fundamental but m/s^2, newton, joule, etc are derived units
Lawrence experienced a major accident in class. His entire test tube rack with all his chemicals fell and broke. There were chemicals all over the floor. Which would be used to clean his mess? eye wash safety shower sponge chemical spill kit
Answer:
The correct option is;
Chemical spill kit
Explanation:
When cleaning simple chemical spills that do not spread or indirectly put people and property in danger and does not negatively impact o the environment the risk, quantity and likely impact of the spill should be evaluated then with a chemical spill kit which comprises of personal protective clothing, materials that are absorbent, waste bags, broom and dustpan and a waste container can be used absorb, contain the residues, clean the spill and put the collected waste away.
Answer:
Chemical spill kit
Explanation:
uh yeah
A balloon is filled with 0.250 mole of air at 35 degrees celsius. If the volume of the balloon is 6.23 liters, what is the absolute pressure of the air in the balloon?
Answer:
pressure = 1.014atms
Explanation:
use ideal gas
PV=nRT
P = (0.250 x 0.08206 x 308)/(6.23)
P = 1.014 atm
The number of joules needed to raise the temperature of 32 g of water from 12 °C to 54 °C is
The specific heat of water is 4.184 J/g °C.
Answer: 5,600 J
Explanation:
Joules = mass x specific heat x temperature change
32 x 4.184 x (54 - 12)
= 133.888 x 42
= 5,623.296
(significant figures => 5,600)
how do we solve a WEAK/STRONG acid
Answer:
Strong acids completely dissociate into their ions in water, while weak acids only partially dissociate. There are only a few (7) strong acids, so many people choose to memorize them. All the other acids are weak.
Explanation:
Weak acids. Explaining the term "weak acid" A weak acid is one which doesn't ionise fully when it is dissolved in water. Ethanoic acid is a typical weak acid. It reacts with water to produce hydroxonium ions and ethanoate ions, but the back reaction is more successful than the forward one.
A strong acid is an acid which dissociates completely in water. That is, all the acid molecules break up into ions and solvate (attach) to water molecules. Therefore, the concentration of hydronium ions in a strong acid solution is equal to the concentration of the acid.
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The freezing point of water in degrees Celsius is [ Select ] __________. The freezing point of water in degrees Fahrenheit is [ Select ] __________. The freezing point of water in Kelvin is [ Select ] __________. (Use whole numerals/numbers for all choices — no letters or symbols)
Answer: 0, 32 , 273
Explanation:
The freezing point of water in degree Celsius, Fahrenheit and Kelvin are in the following order; 0 , 32 , 273
A metal sample is heated and placed into the water in a calorimeter at room temperature. Which statement best describes how the calorimeter can be used to determine the specific heat capacity of the metal sample? Energy transfers to the metal from the water and calorimeter until they are all at room temperature. Energy transfers from the metal to the water and calorimeter until they are all at room temperature. Energy transfers to the metal from the water and calorimeter until they all reach a single temperature. Energy transfers from the metal to the water and calorimeter until they all reach a single temperature.
Answer:
Energy transfers from the metal to the water and calorimeter until they are all at room temperature.
Explanation:
Calorimetry is the process that is used to determine the amount of heat that has been transferred in any process. In any chemical or physical process, the amount of energy is required. This energy is measured by the process of calorimetry. A calorimeter is a device that is used in this process. The heat that has been used in the process is measured and the change in the temperature is noted.
Answer:
b
Explanation:
Other than carbon being relatively small, what is another reason that carbon can form so many compounds? the ability to form four covalent bonds the ability to change shape the ability to form a diatomic molecule the ability to split its electrons
Answer:
Ability to form four covalent bonds.
Explanation:
Carbon is the first member of group 14. It is essentially a nonmetal. It is a small atom which regularly exhibits tetra valency. This means that carbon is able to form four covalent bonds to four chemical species which may be the same or different each time. This leaves room for many different possible combination patterns of carbon with other chemical species.
Hence carbon forms a very large number of compounds due to its small size and its ability for form four covalent bonds to other chemical species in any bonding situation.
Answer: the ability to form four covalent bonds
Explanation:
Why is the mole important? Group of answer choices It can be applied to any type of object: molecules, atoms, ions, etc. It gives us a convenient way to express large numbers. It is useful when converting between grams and atoms or molecules. All of the above.
Answer: the mole
Explanation:
The mole is the unit of amount in Chemistry.
It provides a bridge between the atom and the macroscopic amounts of material that we work with in the laboratory.
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What is the mass of 15% of solution of lime that is formed by dissolving 30g of calcium hydroxide in water?
Answer:
200 grams is the mass of 15% of the solution of lime that is formed by dissolving 30g of calcium hydroxide in water.
Explanation:
Mass of solution = M
Mass percentage of the solution of lime = 15%
Mass of lime or calcium hydroxide = m = 30 g
The Formula of mass percentage is given as :
[tex]m/m\%=\frac{m}{M}\times 100[/tex]
On substituting the values in ab above formula :
[tex]15\%=\frac{30 g}{M}\times 100[/tex]
[tex]M=\frac{30 g}{15}\times 100=200 g[/tex]
200 grams is the mass of 15% of the solution of lime that is formed by dissolving 30g of calcium hydroxide in water.
The radioisotope phosphorus-32 is used in tracers for measuring phosphorus uptake by plants. The half-life of phosphorus-32 is 14.3 days. How much time is required for the activity of a sample of phosphorus-32 to fall to 7.34 percent of its original value
Answer:
54 days
Explanation:
We have to use the formula;
0.693/t1/2 =2.303/t log Ao/A
Where;
t1/2= half-life of phosphorus-32= 14.3 days
t= time taken for the activity to fall to 7.34% of its original value
Ao=initial activity of phosphorus-32
A= activity of phosphorus-32 after a time t
Note that;
A=0.0734Ao (the activity of the sample decreased to 7.34% of the activity of the original sample)
Substituting values;
0.693/14.3 = 2.303/t log Ao/0.0734Ao
0.693/14.3 = 2.303/t log 1/0.0734
0.693/14.3 = 2.6/t
0.048=2.6/t
t= 2.6/0.048
t= 54 days
differentiate between short period and long period
The question is incomplete. The complete question is as follows:
Differentiate between a short period and long period production functions.
Answer:
Difference between a short period and long period production functions is as follows:
Short period: During this period at least one of the factors of production is available in a fixed quantity. For example: Framers having fixed land for growing crops.
Long period: During this period all the factors of production are variable. So change in any variable can increase the production.
Q. Give reasons for the following: 1. Graphite has a very high melting point. 2. Graphite is a non-metal but conducts electricity. Answer the question according to the class 9th student.
Explanation:
1.Graphite has a very high melting point because its structure consists of carbon atoms which are held together by strong covalent bonds
2.It has delocalised electrons.
State and explain the observations when chlorine gas is bubbled through a solution of
fresh iron (II) sulphate solution.
Answer:
A reduction-oxidation (redox) reaction will occur.
Chlorine gas (Cl2) will accept electrons to form Cl- ions.
The Iron(II) ions (Fe2+) will lose electrons to form Fe3+ ions. (Iron (III) ions)
Fe2+ ions are green, while Fe3+ ions are yellow,
so the observation will be the solution turning from green to yellow.
What did the photoelectric experiment demonstrate?
A. Light can cause electrons to be released from the surface of a
metal.
B. Light can deposit electrons on a metal surface.
C. Light can make metal atoms move around, producing electricity.
D. Light can heat metal enough to produce electricity.
Explanation:
When an electromagnetic wave like light hits a material, the electrons gets emitted. The emission of electrons is called photoelectric effect. The emitted electrons are called photoelectrons. In this process the transfer of energy takes place from light to an electron.
Hence, the correct option regarding the photoelectric experiment is (A) " Light can cause electrons to be released from the surface of a metal."
What are some similarities and differences between group 1, 0 and 7 elements on the periodic table?
Answer:
Difference : group 1 elements are known as alkali metals, group 7 elements are known as transition metals
Similarities : Both group 1 and 7 elements become more reactive as u go down and up respectively