Answer:Two Main Types of Pure Substances
Elements and compounds are the two types of pure substances. Examples of common elements include carbon, nitrogen and hydrogen. They consist of one type of atom and cannot break down into something else. Every pure carbon substance, for example, has the same particles in it.
Explanation:I think
8 You are given 20.00g of a dry mixture of sand and table salt.
After adding water and filtering, you are left with wet sand on
the filter paper. The filter paper and sand is then dried and the
mass of the dry sand alone is found to be 5.00g. What was the
% sand in the original mixture?
Answer:
[tex]\%sand=25\%[/tex]
Explanation:
Hello.
In this case, given the mass of the mixture, we can define it in terms of the mass of sand and table salt as shown below:
[tex]m_{sand}+m_{salt}=20.00g[/tex]
Moreover, as after filtering, the mass of dry sand turns out 5.00 g, we can compute the % sand in the original mixture by dividing this value over the mass of the mixture as shown below:
[tex]\%sand=\frac{m_{sand}}{m_{mixture}}*100\%\\ \\\%sand=\frac{5.00g}{20.00g}* 100\%\\\\\%sand=25\%[/tex]
Best regards!
Discuss the relationship between atoms, elements and compounds. Include in your discussion if these are mixtures or pure substances and why.
Answer:
Elements are the simplest complete chemical substances. Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom. Each atom type contains the same number of protons.
Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.
Explanation:
A black object appears black because it reflects all light , and does not absorb any light. True or False
Answer:
False
Explanation:
It is the other way round, a black object appears black because it absorbs all the wavelength of light and does not reflect any light.
A black bucket will appear black because, it absorbs all wavelength of light incident on it. No other wavelength is reflected from the surface of the body. A black color suggests that a body is not reflecting any color. Instead such a body absorbing all the colors. For a white object, they reflect all the wavelength that is incident upon them.On average, about ____________ of incoming solar radiation is reflected back to space.
A 50%
B 30%
C 20%
D 10%
The prefix for one-millionth is micro-.
True
False
Calculate the mass (in g) of 2.60 x 10^23 molecules of PbSO 4. The molar mass of PbSO 4 is 303.27 g/mol.
Answers:
986 g
7.27 g
1.04 g
131 g
4.74 x 1049 g
Explanation:
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[14/10 12:55 p. m.] Vicky Acpo je je je
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How to calculate calories
Answer:If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2.
If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375.
Explanation:
) Do you think the pH of 1,0 M tri-methyl ammonium (CH3)3NH+, pKa = 9.80, will be higher or lower than that of 1.0 M phenol, C6H5OH? What is the difference in pH values for the two acids?
Answer:
1. The pH of 1.0 M trimethyl ammonium (pH = 1.01) is lower than the pH of 0.1 M phenol (5.00).
2. The difference in pH values is 4.95.
Explanation:
1. The pH of a compound can be found using the following equation:
[tex] pH = -log([H_{3}O^{+}]) [/tex]
First, we need to find [H₃O⁺] for trimethyl ammonium and for phenol.
Trimethyl ammonium:
We can calculate [H₃O⁺] using the Ka as follows:
(CH₃)₃NH⁺ + H₂O → (CH₃)₃N + H₃O⁺
1.0 - x x x
[tex]Ka = \frac{[(CH_{3})_{3}N][H_{3}O^{+}]}{[(CH_{3})_{3}NH^{+}]}[/tex]
[tex] 10^{-pKa} = \frac{x*x}{1.0 - x} [/tex]
[tex] 10^{-9.80}(1.0 - x) - x^{2} = 0 [/tex]
By solving the above equation for x we have:
x = 0.097 = [H₃O⁺]
[tex] pH = -log([H_{3}O^{+}]) = -log(0.097) = 1.01 [/tex]
Phenol:
C₆H₅OH + H₂O → C₆H₅O⁻ + H₃O⁺
1.0 - x x x
[tex]Ka = \frac{[C_{6}H_{5}O^{-}][H_{3}O^{+}]}{[C_{6}H_{5}OH]}[/tex]
[tex] 10^{-10} = \frac{x^{2}}{1.0 - x} [/tex]
[tex] 1.0 \cdot 10^{-10}(1.0 - x) - x^{2} = 0 [/tex]
Solving the above equation for x we have:
x = 9.96x10⁻⁶ = [H₃O⁺]
[tex] pH = -log([H_{3}O^{+}]) = -log(9.99 \cdot 10^{-6}) = 5.00 [/tex]
Hence, the pH of 1.0 M trimethyl ammonium is lower than the pH of 0.1 M phenol.
2. The difference in pH values for the two acids is:
[tex] \Delta pH = pH_{C_{6}H_{5}OH} - pH_{(CH_{3})_{3}NH^{+}} = 5.00 - 1.01 = 4.95 [/tex]
Therefore, the difference in pH values is 4.95.
I hope it helps you!
What two particles make up matter?
Answer:
Protons,electrons,and neutrons make up matter
Explanation:
i studied this so hope it helps
An element has 20 protons, 22 neutrons and 18 electrons. What is the charge for this ion?
PLZ HELP I'LL AWARD BRAINLIEST
Answer:
20 protons.
Explanation:
20 protons = 20 + charges
18 electrons = 18- charges.
The difference = 20 - 18 = +2
The charge for this ion is plus 2
It is a calcium ion. The element is number 20 on the periodic table.
The charge of the ion is +2
HOW TO DETERMINE THE CHARGE OF AN ION:
The charge of an ion is a function of the number of protons and electrons in the atom. An atom consists of three subatomic particles namely: neutron, proton and electron. The proton is positively charged while the electron is negatively charged. The charge of an atom is determined by subtracting the number of electrons from protons, that is;Charge = no. of protons - no. of electronsHence, if the protons in an atom is more than the electrons, the charge will be positive and vice versa. In this case, an element has 20 protons, 22 neutrons and 18 electrons.Therefore, the charge of the ion will be 20 protons - 18 electrons = +2
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List the following bonds in order of increasing ionic character: potassium to iodine, carbon to oxygen, lithium to fluorine, boron to fluorine. (Enter the two elements of the bond into the appropriate box: KI, CO, LiF, BF)
Answer:
CO < BF < KI < LiF
Explanation:
The magnitude of ionic character in a bond is dependent on the magnitude of electronegativity difference between the atoms in the bond.
Remember that no bond is 100% ionic or covalent according to Linus Pauling. However, the percentage ionic character depends on electronegativity difference between the bonding atoms and polarizability (Fajan's rules).
Between LiF and KI, Fajan's rules become very important. The Li^+ is small and highly polarizing. The stronger the polarising power of the cation and the higher the polarisability of the anion the more covalent character is expected in a bond
Explain How does its structure affect its function
Answer:
What are we talking about here?
Explanation:
Define waves in your own words.
Answer:
Waves is the disturbance or variation that transfer energy from one location to other
Answer:
this is not in my words but i think this will help
(put some of the words you would use in this)
Explanation:
Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves. ... Longitudinal waves are always characterized by particle motion being parallel to wave motion.
hope i helped
What is the Lewis dot structure for SiS2
Answer:
What Is The Molecular Shape Of A Silicon Disulfide Molecule, SiS2 Trigonal Planar None Of Above Tetrahedral Linear Bent Trigonal Pyramidal 13.
Explanation:
The Lewis structure of SiS₂ shows the 4 valence electrons of Si, which are shared with each sulphur atoms and sulphur in turn shares two valence electrons with Si atom.
What is Lewis dot structure ?The Lewis dot structure of a compound shows all the valence electrons as dots around its atom. From the dot structure we can identify, which electron pairs are bonded , which are non-bonded and which are unpaired electrons.
SiS₂ is a covalent compound formed through the electrons sharing between two sulphur and one silicon atoms. The silicon atom contains 4 valence electrons and one sulphur atom contains 6 valence electrons.
Si needs to gain 4 electrons and one S atom needs to gain 2 more electrons into their valence shell to achieve octet. Hence, One Si shares two electron to each S and S in turn shares its two electron with Si as shown in the image below.
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Use the drop-down menu to complete the statement.
Atoms of elements in the same group have the same number of
. This is why they have similar chemical properties.
Answer:
valence electrons
Explanation:
other guy was close enough
Atoms of elements in the same group have the equal number of valence electrons. That is why they have similar chemical properties.
Why does the element in the same group have similar chemical behavior?The chemical properties of elements depend on the number of valence electrons in their outermost shell. Those elements which are placed in the same group in the periodic table have the same number of valence electrons.
Therefore, elements present in the same group of the modern periodic table have similar chemical behavior.
The elements having a similar valence shell electronic configuration in their atoms are arranged in the same group of the periodic table. These valence electrons decide the chemical properties and reactivities of the chemical elements.
For example, all the elements in group 1 of the periodic table have one electron in their valence shell and all the elements present in group 17 have seven electrons in their valence shell.
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Is air a homogeneous heterogeneous mixture or substance
Answer:
look at the explanation
Explanation:
The air that you breathe is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth's atmosphere has a different density, each layer of air is its own homogeneous mixture.
Hope this helps. :)
When an aqueous sodium hydroxide solution of sodium benzoate is acidified, what precipitate is formed, and why does it precipitate?
Answer:
Insoluble benzoic acid is formed
Explanation:
When benzoic acid is dissolved in sodium hydroxide solution, sodium benzoate is formed. This compound is highly soluble in the aqueous layer.
If this solution is now acidified, the equilibrum position shifts towards the undissociated benzoic acid and a precipitate appears.
An insoluble substance formed during crystallization or precipitation is called a precipitate. The precipitate of the reaction formed is of benzoic acid.
What is a precipitation reaction?A precipitation reaction is a type of reaction in which an insoluble salt or substance is formed as the result of the reaction between the soluble salt solutions.
The substance or the salt produced that does not get dissolved in the solution is called a precipitate.
In the reaction, benzoic acid reacts with the sodium hydroxide salt and forms sodium benzoate salt as shown,
[tex]\rm C_{6}H_{5}COOH(s) + NaOH(aq) \rightarrow C_{6}H_{5}COO^{-}Na^{+}(aq) + H_{2}O(l)[/tex]
When the salt of sodium benzoate is acidified then the precipitation of benzoic acid is formed. The precipitate occurs because the equilibrium shifts towards the undissociated benzoic acid.
Therefore, a precipitate of benzoic acid is formed.
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SOMEONE PLEASE HELPPP
A big bully is having a tug-of-war with a small child. There is a ball attached to the middle of the rope.
Toward whom will the ball move?
Answer:
the ball will move towards the big bully
Ten moles of hydrogen are allowed to react with 6 moles of oxygen. How much water will be
obtained from reaction on complete consumption of one gas?
Answer:
10 moles of water are produced,
Explanation:
Given data:
Moles of H = 10 mol
Moles of O = 6 mol
Water obtained = ?
Solution:
Balance chemical equation:
2H₂ + O₂ → 2H₂O
Now we will compare the moles of H₂ and O₂ with water from balance chemical equation.
H₂ : H₂O
2 : 2
10 : 10
O₂ : H₂O
1 : 2
6 : 2×6 = 12
Number of moles of water produced by hydrogen are less so hydrogen will be limiting reactant and it will limit the yield of water thus, 10 moles of water are produced.
convert 575.1 mmHg to atm
Answer:
= .7567105263
Explanation:
1 atm = 760 mmHg
575.1 mmHg (1 atm/760mmHg) = .7567105263 atm
Kc = 3.07 x 10-4 at 24°C for 2NOBr(g) ↔ 2NO(g) + Br2(g). If the initial concentration of NOBr = 0.878 M, what is the equilibrium concentration (in M to 4 decimal places) of NO?
Answer:
The equilibrium concentration of NO is 0.02124 M.
Explanation:
Given that,
Initial concentration of NOBr = 0.878 M
[tex]k_{c}=3.07\times10^{-4}[/tex]
Temperature = 24°C
We know that,
The balance equation is
[tex]2NOBr\Rightarrow 2NO+Br_{2}[/tex]
Initial concentration is,
[tex]0.878\Rightarrow 0+0[/tex]
Concentration is,
[tex]-2x\Rightarrow 2x+x[/tex]
Equilibrium concentration
[tex]0.878-2x\Rightarrow 2x+x[/tex]
We need to calculate the value of x
Using formula of concentration
[tex]k_{c}=\dfrac{[NO][Br_{2}]}{[NOBr]^2}[/tex]
Put the value into the formula
[tex]3.07\times10^{-4}=\dfrac{[2x][x]}{[0.878-2x]^2}[/tex]
[tex]2x^2=3.07\times10^{-4}\times(0.878)^2+3.07\times10^{-4}\times4x^2-2\times2x\times0.878\times3\times10^{-4}[/tex]
[tex]2x^2=0.0002367+0.001228x^2-0.0010536x[/tex]
[tex]2x^2-0.001228x^2+0.0010536x-0.0002367=0[/tex]
[tex]1.998772x^2+0.0010536x-0.0002367=0[/tex]
[tex]x=0, 0.01062[/tex]
We need to calculate the equilibrium concentration of NO
Using formula of concentration of NO
[tex]concentration\ of\ NO=2x[/tex]
Put the value of x
[tex]concentration\ of\ NO=2\times0.01062[/tex]
[tex]concentration\ of\ NO=0.02124[/tex]
Hence, The equilibrium concentration of NO is 0.02124 M.
which describes bedrock?
a. consist of a solid rock
b.lies directly above the soil layer
c, does not contain weathered rock
d. forms from decomposed material
informative essay on bohrs Thomson's and rutherford model of the atom
If 1.02 g of nickel reacted with 750. mL of 0.112 M hydrobromic acid, how much of each will be present at the end of the reaction if you captured the gas in a 2.50 L vessel at 30 C
Answer:
35.1% is percent yield
Explanation:
Full question: Assume no volume change. If you formed 0.0910 atm of gas, what is the percent yield?
The reaction that is occurring is:
Ni + 3HBr → NiBr₃ + 3/2H₂(g)
First, we will determine moles of Ni and HBr to determine limiting reactant and theoretical yield
Using ideal gas law, we can determine the moles of hydrogen formed. Thus, we can find percent yield:
Moles Ni (Molar mass: 58.69g/mol):
1.02g * (1mol / 58.69g) = 0.01738moles Ni
Moles HBr:
0.750L * (0.112mol/L) = 0.084 moles of HBr.
For a complete reaction of the 0.084 moles of HBr you need:
0.084mol HBr * (1 mole Ni / 3 moles HBr) = 0.028 moles of Ni.
As there are just 0.01738 moles of Ni, the Ni is limiting reactant. Assuming a theoretical yield, moles of H₂ produced are:
0.01738moles Ni * (3/2 H₂ / 1 mol Ni) = 0.02607 moles H₂
Now, moles of H₂ produced are:
PV = nRT
PV/RT = n
Where P is pressure (0.0910atm)
V is volume (2.50L)
R is gas constant (0.082atmL/molK)
T is absolute temperature in Kelvin (30°C + 273.15 = 303.15K)
And n are moles
PV/RT = n
0.0910atm*2.50L/0.082atmL/molK*303.15K = n
0.00915 moles = n
And percent yield (Produced moles / Theoretical moles * 100) is:
0.00915 moles / 0.02607moles =
35.1% is percent yieldnoble gas notation for titanium
Answer:
Titanium [Ar] 3d2 4s2
Explanation:
what happens to the temperature of the liquid in a cup of water as some of the water evaporates?
Calculate the atomic mass of nitrogen if the two common isotopes of nitrogen have masses
of 14.003 amu (99.63% abundance) and 15.000 amu (0.37% abundance).
All living things are made of one or more cells. Which is true of all cells?
A liquid has a volume of 62.7 mL and a density of 2.59 g/mL. What is its mass? (show all work)
Answer:
162.4
Explanation:
The formula for mass is density* volume so 62.7 multiplied by 2.59 equals 162.393. then you round so your anwser would be 162.4