Answer:
~69.744 moles of Ca
Explanation:
Using Avogadro's constant , we know that:
1 mole = 6.022 x 10^23 atoms
S0, the number of moles in 4.20 x 10^25 atoms of Ca:
=(4.20 x 10^25 x 1 )/(6.022 x 10^23)
~69.744 moles of Ca
Q2:How many atoms are in 0.35 moles of oxygen?
1 mole = 6.022 x 10^23 atoms
S0, the number of atoms in 0.35 moles of oxygen:
=[0.35 x (6.022 x 10^23)]
=2.1077 x 10^23 atoms of Oxygen
Hope it helps:)
If the volume of water in a cylinder is 8.0mL, but changes to 10.0mL when a solid is carefully lowered into it, the volume of the solid is?
Answer:
2 mL.
Explanation:
From the question given above, the following data were obtained:
Volume of water = 8 mL
Volume of water + solid = 10 mL
Volume of solid =?
The volume of the solid can be obtained as follow:
Volume of solid = (Volume of water + solid) – (Volume of water)
Volume of solid = 10 – 8
Volume of solid = 2 mL
Therefore, the volume of the solid is 2 mL
What is the name of the molecule formed when two amino acids join
together?
O A. Peptide
B. Nucleic acid
C. Amine
O D. Disaccharide
Peptide is the name of the molecule formed when two amino acids join together. Therefore, the correct option is option A.
What is peptide?
Short strands of amino acids connected by peptide bonds are called peptidides. A polypeptide is a peptide chain that is longer, continuous, and unbranched. Proteins are polypeptides with a molecular weight of 10,000 Dalton or higher. Oligopeptides, which comprise dipeptides, tripeptides, and tetrapeptides, are chains of fewer than twenty amino acids.
Peptides, along with nucleic acids, oligosaccharides, carbohydrates, and others, belong to the vast chemical families of biological polymers or oligomers. Proteins are made up of one or even more polypeptides structured in a biologically useful manner. They are frequently coupled to other proteins, other macromolecules like DNA or RNA, or ligands like coenzymes and cofactors. Peptide is the name of the molecule formed when two amino acids join together.
Therefore, the correct option is option A.
To know more about peptide, here:
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a buffer solution contain 0.1 mole per litres of acetic acid and 0.001 moles perlitre of sodium acetate.what will be its pH?(k=1.8×10-5)
Answer: The pH of the solution is 2.74.
Explanation:
To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:
[tex]pH=pK_a+\log (\frac{\text{[conjugate base]}}{\text{[acid]}})[/tex] .......(1)
The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation for it is:
[tex]pK_a=-log K_a[/tex] ......(2)
The chemical equation for the reaction of acetic acid and NaOH follows:
[tex]CH_3COOH+NaOH\rightleftharpoons CH_3COONa+H-2O[/tex]
Given values:
[tex]K_a=1.8\times 10^{-5}[/tex]
Putting values in equation 2:
[tex]pK_a=-log (1.8\times 10^{-5})\\\\pK_a=4.74[/tex]
We are given:
[tex]CH_3COOH[/tex] = 0.1 M
[tex]CH_3COONa[/tex] = 0.001 M
Plugging values in equation 1:
[tex]pH=4.74+\log (\frac{0.001}{0.1})\\\\pH=4.74-2\\\\pH=2.74[/tex]
Hence, the pH of the solution is 2.74.
Many ski resorts and mountain cities can be reached directly by planes which deposit travelers a mile or more above sea level. This can result in altitude sickness due to hypoxemia, or reduced oxygen in the blood, caused by the unaccustomed exposure to the lower atmospheric pressure at high elevations. On a given day, the prevailing atmospheric pressure in Yellowstone, MT (elevation 2031 meters) might be 0.775 atm. Calculate this pressure expressed in mmHg and in torr.
Answer:
589 torr or mmHg.
Explanation:
We know that 1 atmospheric pressure is equal to 760 torr or 760 mmHg so calculate 0.775 atm pressure in term of mmHg and torr. We perform the following steps which is
1 atm -------- 760 torr or mmHg
0.775 atm ------- X
By cross multiplication we get
X = 760 x 0.775
X = 589 torr or mmHg
So we can conclude that if 0.775 atm is equals to 589 torr.
What is the perfect composition of calcium in calcium chloride?
Answer: 63.96%.
Explanation:
In 111g of Calcium chloride, there is 40g of Calcium and 71g of Chlorine. Percentage Composition of Chlorine is 63.96%.
Hope This Helps!
please help? Liquid, Chemical Properties, Compounds or Products?
Answer:
They are compounds.
Explanation:
..........
Answer:
compounds!!
Explanation:
...........
Equal masses of gaseous N2 and Ar are placed in separate flasks of equal volume at the same temperature. Tell whether each of the following statements is true or false. a. There are more molecules of N2 present than atoms of Ar. Blank 1 b. The pressure is greater in the Ar flask. Blank 2 c. The N2 molecules collide more frequently with the walls of the flask than do the Ar atoms.
Answer:
c. The N2 molecules collide more frequently with the walls of the flask than do the Ar atoms.
Explanation:
The statements are:
a. There are more molecules of N2 present than atoms of Ar. FALSE. Because 1 mol of molecules of N2 = 28g and 1 mol of molecules of Ar = 40g. As there are equal MASSES, you will have more molecules of N2 than Ar molecules
b. The pressure is greater in the Ar flask. FALSE
Because pressure is directly proportional to amount of molecules. As molecules N2 > Molecules Ar. The pressure is greater in N2 flask
c. The N2 molecules collide more frequently with the walls of the flask than do the Ar atoms. TRUE
The collision probability of N2 is higher because there are more molecules presents
Write the equilibrium expression for the following reactions:
1. 4NH3 (g) + 5O2 (g) ↔ 4NO (g) +6H2O (g)
2. ZrI4 (s) ↔ Zr (s) + 2I2 (g)
3. NH3 (g) + HCl (g) ↔ NH4Cl (s)
Answer:
1. Kc = [NO]⁴ [H₂O]⁶ / [NH₃]⁴ [O₂]⁵
2. Kc = [I₂]²
3. Kc = 1/[NH₃] [HCl]
Explanation:
The equilibrium constant (Kc) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactant raised to their stoichiometric coefficients. It only includes gases and aqueous species.
1. 4 NH₃(g) + 5 O₂(g) ↔ 4 NO(g) + 6 H₂O(g)
Kc = [NO]⁴ [H₂O]⁶ / [NH₃]⁴ [O₂]⁵
2. ZrI₄(s) ↔ Zr(s) + 2 I₂(g)
Kc = [I₂]²
3. NH₃(g) + HCl(g) ↔ NH₄Cl(s)
Kc = 1/[NH₃] [HCl]
What does the number 7 mean in the following example-73Li?
a. The number of protons
b. The atomic mass
c. The atomic number
d. The number of electrons
Answer:
7 is the mass number of li and 3 is the atomic number
a 3
b 7
c 3
d 4
What is the answers?
Is my answer right?
Answer:
I say the correct answers are primary and secondary and teriary.
Explanation:
I say you are right!!
Which one of the following is an example of a difficulty caused by thermal
expansion?
A. milkshakes melting
B. paint chipping off the side of a house
C. buckled railroad tracks on a hot day
D. sagging power lines on a cold day
Answer:buckled railroad tracks on a hot day
Explanation: i just did it
Calculate the pH when (a) 24.9 mL and (b) 25.1 mL of 0.100 M HNO3 have been added to 25.0 mL of 0.100 M KOH solution.
Answer:
Suppose you added some solid NaCl to a saturated solution of NaCl at 20℃ and warmed the mixture to 40℃. What would happen to the added NaCl?
Explanation:
can you help with this one
1. Phosphorous reacts with bromine to form phosphorous tribromide. If 35.0 grams of bromine
reacted and 27.9 grams of phosphorous tribromide are actually formed.
what is the percent yield of phosphorous tribromide (PBr3)?
2 P + 3 Br2 ---> 2 PBr3
(Note that the molar masses: P=30.97g, Br = 79.90g) Show your steps
*
Please help me
Answer:
70.6 %
Explanation:
First step, we define the reaction:
2P + 3Br₂ → 2PBr₃
We determine the moles of reactant:
35 g . 1mol / 159.8 g = 0.219 moles
We assume, the P is in excess, so the bromine is the limiting reagent.
3 moles of Br₂ can produce 2 moles of phophorous tribromide
Then, 0.219 moles may produce (0.219 . 2) /3 = 0.146 moles of PBr₃
We convert moles to mass:
0.146 mol . 270.67 g /mol = 39.5 g
That's the 100 % yield reaction, also called theoretical yield. The way to determine the % yield is:
(Yield produced / Thoeretical yield) . 100
(27.9 / 39.5) . 100 = 70.6 %
Given the following equation: 3C12 (g) + 8NH3 (g) → N2(g) +
ONH4Cl (S)
How many moles of NH3 are required to produce 12 moles of
NH4Cl?
Answer:
The balanced equation will be your greatest asset in Solving this.
The Balanced Equation is
3Cl2 + 8NH3---> N2 + 6NH4Cl
So
From this reaction...
3 moles of NH3 is required to produce 6 moles of NH4Cl
Now the question asked.... How Many Moles of NH3 will be needed to produce 12moles of NH4Cl?...
The answer is simply 6moles of NH3.
Why?
Since 3moles of NH3 produce 6 moles of NH4Cl
It makes sense that
6moles of NH3 will produce 12moles of NH4Cl.
Its a simple Ratio.
Hope this helps...
I'm Open to questions if you have any.
Have a great Day!
Balance the following equation by LCM method.Mg + H2O = Mg(OH)2 + H2
Answer:
Mg + 2H₂O —> Mg(OH)₂ + H₂
Explanation:
Mg + H₂O —> Mg(OH)₂ + H₂
The above equation can be balance as illustrated below:
Mg + H₂O —> Mg(OH)₂ + H₂
There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by writing 2 before H₂O as shown below:
Mg + 2H₂O —> Mg(OH)₂ + H₂
Now, the equation is balanced
****Check***
Element >>>>> Reactant >>>> Product
Mg >>>>>>>>>> 1 >>>>>>>>>>> 1
H >>>>>>>>>>> 4 >>>>>>>>>>> 4
O >>>>>>>>>>> 2 >>>>>>>>>>> 2
The balanced equation of Mg + H2O = Mg(OH)2 + H2 is given as
Mg + 2H₂O —> Mg(OH)₂ + H₂
What is the balance equation?Generally, the equation for the Chemical equation is mathematically given as
Mg + H₂O —> Mg(OH)₂ + H₂
Therefore, We se that we have on the LHS
Mg=1
H=2
O=1
and on The RHS
Mg=1
H=4
O=2
Therefore to balance, we add 2 to H and 1 to O giving
Mg + 2H₂O —> Mg(OH)₂ + H₂
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How can we classify the group of elements by just looking at its valence configuration?
Electron configurations
Valence electrons are electrons used in forming bonds and are in the outer shell of an element.
The bond that occurs can be either an ionic bond or a covalent bond
Valence electron determination using electron configurations.
The main group elements usually have valence electron configurations in the s and p subshells
While the transition elements in the subshells (n-1) d
Further explanation
The location of the elemental groups in the periodic system is determined by the number of valence electrons filling the last sub-shell
The period of an element is determined from the valence shell (the biggest main quantum number (n) )
In an atom, there are levels of energy in the shell and subshell
This energy level is expressed in the form of electron configurations.
Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d, and f. The maximum number of electrons for each subshell is
s: 2 electrons
p: 6 electrons
d: 10 electrons and
f: 14 electrons
Charging electrons in the subshell uses the following sequence:
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.
How many moles would be in 85.OmL of 0.750M KOH?
Answer: There are 0.0637 moles present in 85.0 mL of 0.750 M KOH.
Explanation:
Given: Volume = 85.0 mL (1 mL = 0.001 L) = 0.085 L
Molarity = 0.750 M
It is known that molarity is the number of moles of solute present in liter of a solution.
Therefore, moles present in given solution are calculated as follows.
[tex]Molarity = \frac{moles}{Volume (in L)}\\0.750 M = \frac{moles}{0.085 L}\\moles = 0.0637 mol[/tex]
Thus, we can conclude that there are 0.0637 moles present in 85.0 mL of 0.750 M KOH.
The base area of a pyramid is 1,225m2.if the pyramid is 11.3m high,what is it's volume
Answer:
Volume = 4614 m³
Explanation:
The volume of a pyramide is given by the following formula:
Volume = 1/3 * base area * heightWe are already given all the required information to calculate the volume by inputting the data:
Volume = 1/3 * 1225 m² * 11.3 mVolume = 4614 m³The pyramid's volume is 4614 cubic meters.
1. Rearrange the letters to form a word.
1. OOTPSIL
2. BCDEROK
3. UHMSU
4. AOML
5. LCYA
science po ito
1- Topsoil
2- Bedrock
3- Humus
4- Loam
5- Acyl, Clay, or Lacy
Well that was fun :)
Answer:
Explanation:
1. TOPSOIL
2. BEDROCK
Im stuck on these two questions anyone have the right answer?
Calculate the percent composition by mass of iron in Fe(NO3)3
Answer:
It's 23.14 percent
Explanation:
First, the mass of all the elements are:
N = 14
O = 16
Fe = 56
In this molecule you have 3 atoms of N, and 9 atoms of O, so:
3•14 = 42
16•9 = 144
The whole mass of the molecule is:
56 + 42 + 144 = 242
242/100 = 2.42, so 1% is 2.42
56/2.42 = 23.14%
Zirconium has an atomic number of 40, And an atomic mass of 91. How many electrons does zirconium have?
A. 91
B. 51
C. 40
D. 131
Answer:
40
Explanation:
because the atomic number is how many electrons
are either positively charged or negatively charged species in which the number of protons and electrons are not equal. ____________ bonds are chemical bonds that results from the sharing of electrons. ____________ are positively charged ions with more ____________ than ____________ . ____________ ion is an example of a polyatomic anion. ____________ is the system of assigning an unambiguous name to a compound.
Answer:
1. Ions are either negatively or positively charged species in which the number of electrons and protons are not equal.
2. The chemical bond that arises due to the sharing of electrons is termed a covalent bond.
3. The positively charged ions are called cations, which comprise more protons than electrons.
4. An example of a polyatomic anion is the hydroxide anion.
5. The system of assigning an unambiguous name to a compound is called nomenclature.
a. acidic
b. basic
; neutral
d. will not be affected
Find the molarity of 10% NaOH.[MOE 2003
a. 1.5
b! 2.5
c. 4
d. 0.4
10 ml of 2.5 N NaOH is mixed with 20 ml of
N HCI. The mixture is diluted to 100 ml. WI
is the nature of mixture?
IMOF 20
1. You didn't post the question to Number 1.
2.
10% means There's 10g in 100ml of this solution.
This is the weight/volume(w/v) expression of concentration.
So
We have Mass =10g
volume =100ml
Molarity = Moles of solute/volume of solution(in LITRES)
Moles=Mass/Molar mass
Molar mass of NaOH=40g/mol
Mole=10/40
=0.25mole
Volume =100ml =0.1Litres
MOLARITY=0.25/0.1 =
=2.5M
OPTION B.
3. NOTE: THE MOLARITY AND NORMALITY OF NAOH AND HCL ARE THE SAME(This doesn't happen for all compounds tho)
So We can take 2.5N(Normality) of NaOH to be 2.5M(Molarity) NaOH
I think you forgot to write the Normality of the second one. I'll take it to be 1N. Maybe you can then Input supposed value when you're solving on your own
So
1N HCl is same as 1M HCL
We were given their respective volumes
2.5M NaOH can also be written as 2.5mole/volume(in Liters)
The volume of NaOH =10ml or 0.01L
Moles = 2.5mole/L x 0.01L
You notice that Liters on top and bottom cancels out... leaving the moles
So
Mole=0.01x2.5 = 0.025moles of NaOH
we're gonna do the same for 1N HCl in 20ml(0.02L)
So
Mole = 1 x 0.02 =0.02moles
Total Mole = 0.02 + 0.025 =0.045moles
The Final Volume is 100ml as stated in the question. It was diluted to 100ml or 0.1L
So
Final Concentration In Molarity
= Total Moles/Volume in L
=0.045/0.1
=0.45M.
1.State two uses of water at home.
2. State two uses of water in industries.
3. What is water conservation?
4. What are some methods of water conservation?
Helppppp!!!!!!
Answer:
1. Washing dishes and cooking
2. Water is used as a solvent in the manufacture of beverages and it is also largely used in agriculture.
3. Water conservation is the action of using water wisely and not wasting it.
4. i) Wash dishes in a tub of water instead of under a running tap.
ii) Use a pail of water to wash the car instead of spraying water from a hose.
iii) Make sure that there are no leaking or broken taps and pipes.
Answer:
Washing dishes and cooking
2. Water is used as a solvent in the manufacture of beverages and it is also largely used in agriculture.
3. Water conservation is the action of using water wisely and not wasting it.
4. i) Wash dishes in a tub of water instead of under a running tap.
ii) Use a pail of water to wash the car instead of spraying water from a hose.
iii) Make sure that there are no leaking or broken taps and pipes.
Explanation:
Which nuclear equation represents a spontaneous decay?
Answer:A
Explanation:
1. [tex]^{222}Rn_{86}[/tex] → [tex]^{218}Po_{84} + ^{4}He_{2}[/tex]
What is a spontaneous decay?
Spontaneous fission (SF) is a form of radioactive decay where an atom's nucleus splits into two smaller nuclei and generally one or more neutrons.Out of the given options, only option 1. [tex]^{222}Rn_{86}[/tex] → [tex]^{218}Po_{84} + ^{4}He_{2}[/tex] is an example of spontaneous decay since an atom nucleus is splitting into two daughter nuclei's.Spontaneous decay would refer to whether or not decay was stimulated by bombardment with neutrons or alphas while random decay refers to the selection of which nuclei actually decayLearn more:
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Water moves on, above or under the surface of the Earth true or false
above because its above
What type of decay changes the atomic number of the atom?
B. Translocation
C. Translation
D. Transuranium
A. Transmutation
Answer:
d
Explanation:did test
The solubility of an ionic compound can be expressed as the number of moles of the compound that will dissolve per liter of solution (molarity). The saturated solution has approximately____(a) sodium ions dissolved in it (give an estimate of the average value.) The solution (not the solid) contains approximately_____(b) moles of sodium ions.
Answer:
Number of moles of sodium dissolved = 6.0 *10^23
Explanation:
The image for the question is attached
Solution
a) Total 181 ions of Na are dissolved
b)
The number of moles of sodium dissolved = 181/6.023 *10^23
Number of moles of sodium dissolved = 5.987 * 10^23
Number of moles of sodium dissolved = 6.0 *10^23
how will you know whether the crystallization point is reached
Answer:
Place a glass rod in the solution, if the crystallisation point has been reached, you should notice small crystals formed on it.