Answer:
The history of basketball began with its invention in 1891 in Springfield, Massachusetts by Canadian physical education instructor James Naismith as a less injury-prone sport than football. Naismith was a 31-year old graduate student when he created the indoor sport to keep athletes indoors during the winters.
Explanation:
The history of basketball began with its invention in 1891 in Springfield, Massachusetts by Canadian physical education instructor James Naismith as a less injury-prone sport than football. Naismith was a 31-year old graduate student when he created the indoor sport to keep athletes indoors during the winters.
When 0.717 g of sodium metal is added to an excess of hydrochloric acid, 7450 J of heat are produced. What is the enthalpy of the reaction as written?
2Na(s)+2HCl(aq)⟶2NaCl(aq)+H2(g)
Answer:
The enthalpy change of the reaction is 4.78 × 10⁴ J.
Explanation:
We are given that 0.717 g of sodium metal reacts with hydrochloric acid to produce 7450 J of heat.
Converting grams of sodium to moles:
[tex]\displaystyle 0.717 \text{ g Na} \cdot \frac{1 \text{ mol Na}}{22.99 \text{ g Na}} = 0.0312 \text{ mol Na}[/tex]
And dividing the amount of heat produced by the moles of sodium reacted yields:
[tex]\displaystyle \Delta H = \frac{7450 \text{ J}}{0.312 \text{ mol Na}} = 2.39 \times 10^4 \text{ J/mol Na}[/tex]
Because the given reaction has two moles of sodium metal, we can multiply the above value by two to acquire the enthalpy change of the given reaction:
[tex]\displaystyle \Delta H = 2\text{ mol Na}\left(2.39 \times 10^4 \text{ J/mol Na}}\right) = 4.78 \times 10^4 \text{ J}[/tex]
In conclusion, the enthalpy change of the reaction is 4.78 × 10⁴ J.
An atom has the following electron configuration.
1s22s22p63s23p64s2
How many valence electrons does this atom have?
Answer:
2
Explanation:
4s2 has 2 valence electrons
Valence shell is the shell which is the outermost shell, that is filled in the last, before valence shell is penultimate shell. Therefore 2 valence electron are there in the valence shell.
What is element?Element generally consist of atoms or we can say atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
From our question the electronic configuration of element is given as
1s²2s²2p⁶3s²3p⁶4s²
Valence electron is the one which is present in the outermost shell or orbit. So, form above electronic configuration we can say that 4 is the outermost shell and in this shell 2 electron is present. Therefore 2 electron are there in the valence shell as valence electron.
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Bio fuel is a mixture of petrol and 20%——————
Answer:
methane and petrol okkkkkkkkkkkkkkkkkkk
True or false? Suppose you have two identical birthday balloons, with one filled with the gas helium and the other blown up by you. Assuming they're both filled to the same amount, these balloons will have the same number of molecules.
Answer:
True!
Explanation:
Avogadro’s law means that if we compare the number of helium molecules and the number of air molecules needed to inflate the same balloon, we would find the numbers the same.
The balloon filled with helium air, and the one blown by oneself with the same amount of air have the equivalent number of molecules. Thus, the given statement is true.
What is the relation between moles and atoms?The moles are given as the mass of the compound with respect to the molar mass. According to the Avogadro's law, the 1 mole of a substance has the presence of the atoms equivalent to the Avogadro number.
In the balloons filled with oneself and individual there is same amount of gas, thus have same moles and thereby the number of molecules will be same in both the balloons. Thus, the given statement is true.
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A solution is prepared by dissolving 15.0 g of pure HC2H3O2 and 25.0 g of NaC2H3O2 in 775 mL of solution (the final volume). Incorrect answer icon Incorrect. Did you use the correct form of the H-H equation
What is a peninsula?
Answer:
A peninsula ( Latin: paeninsula from paene "almost" and insula "island") is a landform surrounded by water on most of its border while being connected to a mainland from which it extends.
Explanation:
CAN I GET BRAINLIEST
How many molecules are present in 4.61x10-2 mol of O2
Answer:
6.02 × 1023
The molar mass from the periodic table is 32.00 g O2 = 1 mol O2, and by definition, 1 mol O2 = 6.02 × 1023 molecules O2.
which one is not allotropes of carbon?
Answer:
B. Activated Carbon
Explanation:
How many atoms are in mercury phosphate
Answer:
There are 95 atoms in mercury phosphate
Explanation:
You just add the atomic number for both elements
People use solution of Na3PO4 to clean walls before putting up wall paper. If the entration is 1.7% (m/v). What mass of Na3PO4 is needed to make 2L of solution?
Answer:
34 grams
Explanation:
Assuming m/v means mass of solute / volume of solvent, then set up the equation:
1.7/100=m/2000, by cross multiplication, m=34 grams
name 2 elements that are liquid at room temperature and describe their colour
Answer:
Bromine
Mercury
Bromine (symbol Br and atomic number 35) is a reddish-brown liquid, with a melting point of 265.9 K. Mercury (symbol Hg and atomic number 80) is a toxic shiny silvery metal, with a melting point of 234.32 K.
Will give Brainliest
Use the image to answer the question.
An illustration shows the process that takes place in a cold pack. The warm cold pack has ammonium nitrate on one side and water on the other. The water is kept separate in a thin plastic bag. The pack is squeezed and the inner bag bursts. The mixture cools as ammonium nitrate dissolves.
Which kind of reaction is shown in this image?
(1 point)
It is an endothermic reaction because the system takes energy from the surroundings.
It is an exothermic reaction because the surroundings take energy from the system.
It is an endothermic reaction because the surroundings take energy from the system.
It is an exothermic reaction because the system takes energy from the surroundings.
Answer:
it is an endothermic reaction because the system takes energy from the surrounding.
Answer:
It is an endothermic reaction because the system takes energy from the surroundings.
Explanation:
I did the test.
What is the limiting reactant from this equation
Answer:
A Option is the correct answer.
Explanation:
The
is the wind system responsible for the movement of weather from west to east across most of the continental United States
A
polar easterlies
B
prevailing westerlies
C
trade winds
Answer:
Westerlies are prevailing winds that blow from the west at midlatitudes. They are fed by polar easterlies and winds from the high-pressure horse latitudes, which sandwich them on either side.Nov 15, C answer
A bike with mass of 10 kg is moving with a speed of 5 m/s. What is the magnitude of its momentum?
Answer:
The momentum is then (10 kg)(5 m/s)= 490.5 kg-m/s
Explanation:
Answer is A
Calculate the pH at the equivalence point for the following titration: 0.25 M HCOOH versus 0.25 M NaOH.
The pH at the equivalence point for the titration of 0.25 M HCOOH versus 0.25 M NaOH is 8.5.
Let's consider the following neutralization reaction.
HCOOH + NaOH ⇒ HCOONa + H₂O
At the equivalence point, 0.25 M HCOOH completely reacted with 0.25 M NaOH to form 0.25 M HCOONa.
HCOONa undergoes hydrolysis. The net ionic equation is:
HCOO⁻(aq) + H₂O(l) ⇄ HCOOH(aq) + OH⁻(aq)
Given the concentration of HCOO⁻ is 0.25 M (Cb) and the basic dissociation constant of HCOO⁻ is 4.8 × 10⁻¹¹ (Kb), we can calculate the concentration of OH⁻ using the following expression.
[tex][OH^{-} ] = \sqrt{Kb \times Cb } = \sqrt{(4.8 \times 10^{-11} ) \times 0.25 } = 3.5 \times 10^{-6} M[/tex]
The pOH of the solution is:
[tex]pOH = -log [OH^{-} ] = -log (3.5 \times 10^{-6} ) = 5.5[/tex]
The pH of the solution is:
[tex]pH = 14 -pOH = 14 -5.5 = 8.5[/tex]
The pH at the equivalence point for the titration of 0.25 M HCOOH versus 0.25 M NaOH is 8.5.
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which has the shorter bond lengths in Alkane,alkene and alkynes
Answer:
alkanes
Alkynes have the strongest bond. Followed by alkenes and then alkanes. This is because in alkynes there are 3 bonds between at least two carbons
Consider the unbalanced chemical equation:
H2SO4 (aq) + Fe(OH)3 (S) → Fe2(SO4)3 (S) + H2O (L)
A volume of 38.0 mL of aqueous H2SO4 solution was required to
react completely with 0.685 g Fe(OH)3 (molar mass = 106.8 g/mol)
to produce Fe2(SO4)3. Calculate the molar concentration of the
H2SO4 solution.
A) 0.253 M
B) 0.344 M
C) 0.214 M
D) 0.301 M
E) 0.175 M
The answer is A. The explanation is in the image.
On the top of the image where it just says equation:, that is part of the sentence "First we need to balance the equation:"
1 question hurry as fast as possible no link
Answer: ELEMENT
Explanation:
Which of these is the condensed structural formula for an alkane with four carbon
atoms?
O CH3CH2CH2CH3
H
HLH
1C
H
C2
LH
I
C
HTH Н
H
0-I
I
क
H
OCH3CHCHCH3
OC-C-C-C
Answer:
First option
Explanation:
The option that says CH3CH2CH2CH3 is the correct option (I hope that I am right because the order of the answers is not very clear :/)
Which two metals shown won't make a solid when combined with anything? 2.2.2
Answer:
aluminum Zicam iron
Explanation:
Which metals dont react with anything?
Metals like aluminium, iron and zinc do not react either with cold or hot water. But they react with steam to form the metal oxide and
How are metals, metalloids, nonmetals grouped
no I will not please put you because that's the god of the Bible
Metals are good conductors of heat and electricity, and are malleable (they can be hammered into sheets) and ductile (they can be drawn into wire).
Nonmetals are (usually) poor conductors of heat and electricity, and are not malleable or ductile; many of the elemental nonmetals are gases at room temperature, while others are liquids and others are solids.
The metalloids are intermediate in their properties. In their physical properties, they are more like the nonmetals, but under certain circumstances, several of them can be made to conduct electricity.
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If an HPLC procedure is running at a pressure of 5.48×10^8 Pa what is it’s running pressure in torr
explain why water wasn't used in crackers?
Calculate the pH when the following quantities of 0.100 M NaOH solution have been added to 50.0 mL of 0.100 M HCl solution
Answer:
see explanation
Explanation:
Given 0.100M NaOH + 50ml 0.100M HCl
If 50ml of 0.100M NaOH is added to 50ml 0.100M HCl => pH = 7
if less than 50ml of 0.100M NaOH => pH < 7
if more than 50ml of 0.100M NaOH => pH > 7.
Example:
50ml(0.100M NaOH) + 50ml(0.100MHCl) =>
0.500mole NaCl + 0.500mole H₂O
In this mix, both NaOH and HCl are converted to NaCl and H₂O and NaOH or HCl are no longer present giving a neutral solution. Since neither Na⁺ nor Cl⁻ undergo hydrolysis, the pH is dependent upon H₂O ⇄ H⁺ + OH⁻ and [H⁺] = [OH⁻] = 10⁻⁷M => pH = -log[H⁺] = -log(10⁻⁷) = -(-7) = 7
If less than 50ml of 0.100M NaOH is added, the mix will have an excess of HCl and the pH will be acidic; i.e., less than 7.
If more than 50ml of 0.100M NaOH is added, the mix will have an excess of NaOH and the pH will be alkaline (basic); i.e., greater than 7.
How many aluminum ions are present in 65.5 mL of 0.210 M All3solution?
Answer:
Aluminium ions present's in 65.5mL of 0.210
M All 3solution is Given below-:
Answer and Explanation: 1
The first step is to determine the moles of aluminum ions. This utilizes the volume, molar concentration, and subscripts from the chemical formula of aluminum (III) fluoride as shown.
65.5 mL×1 L1000 mL×0.210 mol AlF31 L×1 mol Al3+1 mol AlF3=0.013755 mol Al3+65.5 mL×1 L1000 mL×0.210 mol AlF31 L×1 mol Al3+1 mol AlF3=0.013755 mol Al3+
To calculate for the number of aluminum ions, we use Avogadro's number as shown.
0.013755 mol Al3+×6.022×1023 ions1 mol Al3+=8.28×1021 ions Al3+.
Itz the ans. of collage ok man.
Answer:
m0.013755
m
o
l
A
l
3
+
×
6.022
×
10
23
i
o
n
s
1
m
o
l
A
l
3
+
=
8.28
×
10
21
i
o
n
s
A
l
3
+
L
×
1
L
1000
m
L
×
0.210
m
o
l
A
l
F
3
1
L
×
1
m
o
l
A
l
3
+
1
Explanation:
The first step is to determine the moles of aluminum ions. This utilizes the volume, molar concentration, and subscripts from the chemical formula of aluminum (III) fluoride as shown.
65.5. To calculate for the number of aluminum ions, we use Avogadro's number as shown.
why the back torn of camel is important?
The back torn of Camel is important because it acts as a storage facility for
fats.
Camels are found in desert regions where there is scarcity of
Food WaterThis makes the food it eats to get stored at the back in the hump
region as fats so as to enable it survive long periods of unavailability of food.
The fats are gradually metabolized into nutrients which is used by the body
cells to ensure adequate energy availability and optimal survival.
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identify each of the following changes of states as melting ,freezing,sublimation or deposition
a: ice sculpture start breaking down as temperature rise above 0 degree
Answer:
Melting
Explanation:
Ice begins to melt at 0 degrees celsius
Melting is from solid to liquid
Freezing is from liquid to solid
Sublimation is from solid to gas
Deposition is from gas to solid
the role of haemoglobin in the transport of oxygen and carbon dioxide
Hemoglobin with bound carbon dioxide and hydrogen ions is carried in the blood back to the lungs, where it releases the hydrogen ions and carbon dioxide and rebinds oxygen. Thus, hemoglobin helps to transport hydrogen ions and carbon dioxide in addition to transporting oxygen.
A 1.8 mole sample of a compound weighs 195 g and is found to be 11.18% H and 88.82% C. What is the molecular formula for the compound?
Answer:
C8H12
Explanation:
First find the molar mass
195/1.8 × 1 = 108.3 gmol-1
Then the molecular formula
Mass of C in 1 mole of compound = 88.82×108.3/100
= 96.2 g
Mass of H in 1 mol of.the compound = 108.3×11.18/100 = 12.11 g
Divide the mass by their molar masses to get no. of moles in 108.3 g of compound or 1 mole of compound
Moles of C in one Mole of compound = 96.2g/12 gmol-1 = 8 mol
Moles of H in 1 mole of compound = 12.11g/1 gmol-1 =12 mol
Since we need the molecular formula it's C8H12