The heat required : 840 J
Further explanationGiven
mass of water = 20 g
Temperature : 30°C to 40°C
Required
Heat to raise the temperature
Solution
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C (for water= 4.18 J/g° C)
∆T = temperature difference, ° C / K
The heat :
[tex]\tt Q=20\times 4.2\times (40-30)\\\\Q=\boxed{\bold{840~J}}[/tex]
2. what is the molarity of a 300ml solution which is 25%by mass H2S04?
the solutions mass is 353.4g
Answer:
3 M
Explanation:
Molarity is calculated by dividing the moles of the solute by the liters of solution. In this problem, we are given that the mass of the solution is 353.4 g and that the mass of the solute (H2SO4) is 25% of this.
Thus, you get that the mass of the solute is 88.35 g.
Next, you must convert the mass of the solute into moles. You must use the periodic table to find the molar mass of the solute in order to do the conversion.
Thus, you get that the number of moles of solute is 0.90.
Molarity is then = 0.90 mol/.300 L = 3 M.
The molarity of a 300ml solution of mass 353.4 g which is 25%by mass H₂SO₄ is 2.94 molar.It is calculated from the number of moles of sulphuric acid.
What is molarity?Molarity is a term used to represent the concentration of a solution. Mathematically it is the ratio of the number of moles of solute to the volume of solution in liter.
The mass percent of substance is the ratio of mass of that substance to the total mass. Here, the total mass of the solution is 353.4 g and the solute acid is 25% by mass. Thus mass of the solute is :
353.4 × 25 /100 = 88.3 g.
The molar mass of sulphuric acid is 100 g/mol. Thus number of moles of solute is 88.3 g/100 g/mol = 0.88 moles.
The volume of the solution is 300 ml or 0.3 liter. Now, the molarity of the solution can be calculated as follows:
Molarity = no.of moles of solute/volume in L
= 0.88 mol / 0.3 L
= 2.94 mol/L.
Hence, the molarity of the solution is 2.94 molar.
To find more about molarity, refer the link below:
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What is a net ionic equation?
A. An equation that is balan
B. An equation that shows a
Answer:
Explanation:
An equation showing only what is involved in the reaction.
a o e x
How many moles are in 34.2 g Ca
Answer:
0.855 moles are present in 34.2 g of Ca
If you have 2 of the same substance and they are at the same temperature but have a different amount, what changes?
Answer:
The heat energy stored within them changes
Explanation:
Heat energy is a function of the mass of a body, its specific heat capacity, and its temperature.
In this case, the bodies have the same specific heat capacity since they are made from the same material and the same temperature.
To get the quantity of heat stored in a body, we need to multiply all three parameters as shown below
[tex]Q = mC \Delta T[/tex]
An increase in mass, through an increase in the amount of substance of a material present, will cause a corresponding increase in the heat energy stored within the material
Name 3 types of rock on Planet Earth.
Answer:
igneous, sedimentary, and metamorphic
Explanation:
Answer:
IGNEOUS ROCKS form when molten rock (magma or lava) cools and solidifies. SEDIMENTARY ROCKS originate when particles settle out of water or air, or by precipitation of minerals from water.
And METAMORPHIC (I dont have nothing for this won)
Explanation:
1. Which type of blood cell is the most numerous in the body?
O a. red blood cells
O b. white blood cells
c. platelets
d. plasma
Answer:
red blood cells
Explanation:
I'm not so sure though
point Deshawn ran the 400 m race(in a straight line) in 2 minutes. What is his distance and displacement ? Explain your answer below in complete sentences.
His distance and displacement are the same, which was 400 m
Further explanationGiven
Distance = 400 m
time = 2 min
Required
Distance and displacement
Solution
Distance is a scalar quantity that indicates the length of the trajectory that is traveled by an object within a certain interval. Distance has no direction, only has magnitude
Can be simplified distance = totals traveled
Displacement is a vector quantity that shows changes in the position of objects in a certain interval of time. Displacement has magnitude and direction
Can be simplified displacement = distanced traveled from starting point to ending point
From the definition above shows that the displacement and the distance that he traveled have the same value (magnitude), which is equal to 400 m
The value of the two will be different if he starts and finishes at the same point, then the displacement value is zero while the distance he has traveled is still 0
Which is not true of the ideal gas law?
-For a given amount of gas held at constant temperature, the product of pressure and
volume is constant.
-It describes the behavior of an ideal gas in terms of the pressure, volume,
temperature, and number of moles of gas present.
-None of the above.
-The value of R is 0.082.1 L.atm/mol.K.
Answer:
For a given amount of gas held at constant temperature, the product of pressure and
volume is constant.
:
Which of the following double-replacement reactions will occur?
NaBr(aq) + AgNO3(aq) →
NaBr(aq) + Ca(NO3)2(aq) →
NaBr(aq) + Al(NO3)2(aq) →
NaBr(aq) + KNO3(aq) →
NaBr(aq) + AgNO3(aq) →NaNO3(aq) + AgBr(s)⇒ double-replacement reactions will occur
Further explanationDouble-Replacement reactions. Happens if there is an ion exchange between two ion compounds in the reactant to form two new ion compounds in the product
A double replacement reaction will occur if one or both of the products is an insoluble precipitate, a liquid, or a gas
To predict whether this reaction can occur or not is one of them, the precipitation reaction. A precipitation reaction occurs if two ionic compounds which are dissolved reacted to produce one of the products of the ion compound does not dissolve. Formation of these precipitating compounds that cause reactions can occur
Solubility Rules:
• 1. soluble compound
All compounds of Li +, Na +, K +, Rb +, Cs +, and NH4 +
All compounds of NO₃⁻ and C₂H₃O₂⁻
Compounds of Cl−, Br−, I− except Ag⁺, Hg₂²⁺, Pb²⁺
Compounds of SO₄²⁻ except Hg₂²⁺, Pb²⁺, Sr²⁺, Ba²⁺
• 2. insoluble compounds
Compounds of CO₃²⁻ and PO₄³⁻ except for Compounds of Li +, Na +, K +, Rb +, Cs +, and NH₄ +
Compounds of OH− except Compounds of Li +, Na +, K +, Rb +, Cs +, NH₄⁺ , Sr²⁺, and Ba²⁺
NaBr(aq) + AgNO3(aq) →NaNO3(aq) + AgBr(s)⇒ occur
NaBr(aq) + Ca(NO3)2(aq) → NaNO3(aq) + CaBr₂(aq)⇒not occur
NaBr(aq) + Al(NO3)3(aq) →NaNO3(aq) + AlBr3(aq)⇒not occur
NaBr(aq) + KNO3(aq) →NaNO3(aq) + KBr(aq)⇒not occur
group viia elements are very active non metals give reason
Answer:
because they need only one electron
Which term means that a metal can be made into wire?
A)
Luster
B)
Ductility
Malleability
D)
Conductivity
Answer:
c
Explanation:
i think
MARKING BRAINLIEST! AND 16 POINTS
Plants use energy from sunlight, water, and carbon dioxide to produce sugar. What structure is found only in plant cells and helps plants capture energy from sunlight?
Answer:
Chloroplast.
Explanation:
Answer:
chlorophat
Explanation:
the characterstic part of a molecule that determines its chemical properties is known as
Answer: The atomic number indicates the number of protons within the core of an atom. The atomic number is an important concept of chemistry and quantum mechanics. An element and its place within the periodic table are derived from this concept. ... These electrons mainly determine the chemical behaviour of an atom. The chemical properties of an element, are determined by the number of protons in the nucleus. This number of protons is called the atomic number. The mass of the atom, its atomic mass, depends upon the sum of the number of protons and the number of neutrons present in the nucleus.
Hope this helps....... Stay safe and have a Merry Christmas!!!!!!! :D
Explanation:
Outer Electrons/Valence Electrons determine the chemical properties....Or Somehow we can say in organic compounds, functional group determine mostly chemical properties...
determine the frequency and wavelength (in nm) of the light emitted when the e- fell from n=4 and n=2
Answer:
Frequency = 6.16 ×10¹⁴ Hz
λ = 4.87×10² nm
Explanation:
In case of hydrogen atom energy associated with nth state is,
En = -13.6/n²
For n = 2
E₂ = -13.6 / 2²
E₂ = -13.6/4
E₂ = -3.4 ev
Kinetic energy of electron = -E₂ = 3.4 ev
For n = 4
E₄ = -13.6 / 4²
E₄ = -13.6/16
E₄ = -0.85 ev
Kinetic energy of electron = -E₄ = 0.85 ev
Wavelength of radiation emitted:
E = hc/λ = E₄ - E₂
hc/λ = E₄ - E₂
by putting values,
6.63×10⁻³⁴Js × 3×10⁸m/s / λ = -0.85ev - (-3.4ev )
6.63×10⁻³⁴ Js× 3×10⁸m/s / λ = 2.55 ev
λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s /2.55ev
λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s /2.55× 1.6×10⁻¹⁹ J
λ = 19.89 ×10⁻²⁶ Jm / 2.55× 1.6×10⁻¹⁹ J
λ = 19.89 ×10⁻²⁶ Jm / 4.08×10⁻¹⁹ J
λ = 4.87×10⁻⁷ m
m to nm:
4.87×10⁻⁷ m ×10⁹nm/1 m
4.87×10² nm
Frequency:
Frequency = speed of electron / wavelength
by putting values,
Frequency = 3×10⁸m/s /4.87×10⁻⁷ m
Frequency = 6.16 ×10¹⁴ s⁻¹
s⁻¹ = Hz
Frequency = 6.16 ×10¹⁴ Hz
During photosynthesis, plants take carbon dioxide from the air and water and convert them into:
A. amino acids
B. glucose and oxygen
C. oxygen and chlorophyll
D. water and sunlight
Answer:
c I am pretty sure it's c because I learned this today in science and I think that what it is but if it's not see then it's I don't know
limitation of hydrogen displacement method
Answer:
Limitation of hydrogen displacement method is described below in detailed explanation.
Explanation:
This approach is beneficial for elements that can displace hydrogen from psychedelics or can consolidate with hydrogen. A single replacement effect, sometimes described as a single displacement reaction, is a reflection in which one component is replaced for a different component in a compound. The origin elements are forever pure elements, such as a clear zinc metal or hydrogen propellant, plus an aqueous compound.
CAN SOMEONE HELP ME ON THIS!!! THIS IS VERY URGENT
Answer:
Explanation:
3: Given data:
Number of moles of strontium nitrate = 3.00×10⁻³ mol
Number of atoms = ?
Solution:
There are 9 moles of atoms in 1 mole of Sr(NO₃)₂.
In 3.00×10⁻³ moles,
9 mol × 3.00×10⁻³
27.00×10⁻³ mol
Number of atoms in 3.00×10⁻³ mol of Sr(NO₃)₂:
27.00×10⁻³ mol × 6.022×10²³ atoms / 1mol
162.59×10²⁰ atoms
4)Given data:
Mass of calcium hydroxide = 4500 Kg (4500/1000 = 4.5 g)
Number of moles = ?
Solution:
Number of moles = mass in g/molar mass
by putting values,
Number of moles = 4.5 g/ 74.1 g/mol
Number of moles = 0.06 mol
5) Given data:
Number of atoms of silver nitrate = 1.06×10²³
Number of moles = ?
Solution:
1 mole of any substance contain 6.022×10²³ atoms .
1.06×10²³ atoms × 1 mol / 6.022×10²³ atoms
0.176 moles of silver nitrate
wo people push on the same door from opposite sides as shown.
A man pushes on a door from the left. A woman pushes on the door from the right.
They will only see the door move when
both people exert the same force so that the forces are unbalanced.
neither person exerts a force on the door so that the net force is zero.
one person exerts more force than the other so that the forces are unbalanced.
both people exert the same force so that the forces are balanced.
Answer is:
When one person exerts more force than the other so that the forces are unbalanced........ maybe, im not sure if im right
Answer:
c
Explanation:
How many valence electrons does Florine have?
O 5
O 7
3
9
Answer:
When forming ions, elements typically gain or lose the minimum number of electrons necessary to achieve a full octet. For example, fluorine has seven valence electrons, so it is most likely to gain one electron to form an ion with a 1- charge
Explanation:
Answer:
7
Explanation:
a-P-e-X
The standard cell potential for : 3A(s) + B+3(aq) → 3A+(aq) + B(s) is E° = 2.00 V. How does Ecell compare to Eo when [A+] = 0.50, [B3+] = 1.5 x 10-3 at 298 K.
E cell = 1.962 V
Further explanationGiven
E° cell = 2.00 V
Required
E cell at 298 K
Solution
The potential cell for nonstandard conditions we can use the Nernst equation
[tex]\rm E = E ^ o -\dfrac {RT} {nF} lnQ[/tex]
For temperature T = 298 K,
[tex]\rm E = E ^ o -\dfrac {0.0592V} {n} log \: Q[/tex]
Reaction
3A(s) + B+3(aq) → 3A+(aq) + B(s)
Half Reaction
3A(s)⇒3A⁺(aq)+3e⁻
B⁺³(aq)+3e⁻⇒B(s)
n = 3 (3 electron transfer)
Q = the reaction quotient :
[tex]\tt Q=\dfrac{[A^+]^3}{[B^{+3}]}=\dfrac{0.5^3}{1.5.10^{-3}}=83.3[/tex]
E cell :
[tex]\tt E_{cell}=2-\dfrac{0.0592}{3}log~83.3\\\\E_{cell}=1.962~V[/tex]
Hello there please help this is for science and if you answer thanks for the help you earned yourself a 5 star.
Answer:
Ice cubes, glass of tea, and butter
Explanation:
Like it said in the hint, the molecules will only speed up if they gain heat. This means in order for the object to heat up it will have to have a temperature that is less than the temperature in the room. Ice cubes, glass of tea, and butter are the three objects that have a temperature less than 72 degrees so when they are placed in the 72 degrees room they will heat gain heat (therefore making the molecules move faster)
HELP!!!
find the balanced equation
Answer:
3Fe²⁺ + Cl₂ ⇒ 2Fe³⁺ + 2Cl⁻
Explanation:
manipulate the problem to match charges and have the same amount of reactants and products on both sides.
When a car burns gas most of the energy is lost as heat. This inefficiency of energy transfer is an example of which law of energy?
A. second
B. fourth
C. first
D. third
Answer:
C) first
Explanation:
How many moles of CO2 can form from 5.1 moles of C3H8 and abundant O2 in the equation:
C3H8 + 5O2 -> 3CO2 + 4H2O
Answer:
15.3 moles of CO₂ formed.
Explanation:
Given data:
Number of moles of CO₂ formed = ?
Number of moles of C₃H₈ react = 5.1 mol
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + H₂O
Now we will compare the moles of CO₂ with C₃H₈.
C₃H₈ : CO₂
1 : 3
5.1 : 3/1×5.1 = 15.3 mol
Dust storms in the Sahara desert carry mineral nutrients across the Atlantic Ocean to replenish the supply leached out of the soils of the Amazon basin. What was an important mineral fertilizer delivered this way, mentioned in the video?
Answer:
Phosphorus.
Explanation:
Phosphorus is the important fertilizer which comes through the dust storms of Sahara desert and provides this nutrient to the soils of the Amazon basin. Phosphorus is an important macronutrient that is necessary for the growth and development of plants so we can conclude that this dust storms are very important for the fertility of the soils present in Amazon basin.
Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm8 at 27 ∘C. (R = 0.083 bar dm8 K−1 mol−1
Answer:
Total pressure = 56.77 bar
Explanation:
Given data:
Mass of dioxygen = 8 g
Mass of dihydrogen = 4 g
Volume of vessel = 1 dm³
Temperature = 27°C (27+273 = 300 K)
R = 0.083 bar.dm³ / mol.K
Total pressure = ?
Solution:
Number of moles of dioxygen:
Number of moles = mass/molar mass
Number of moles = 8 g/ 32 g/mol
Number of moles = 0.25 mol
Pressure of dioxygen:
PV = nRT
P = nRT/V
P = 0.25 mol × 0.083 bar.dm³ / mol.K × 300 K / 1 dm³
P = 6.97 bar.dm³ /1 dm³
P = 6.97 bar
Number of moles of dihydrogen:
Number of moles = mass/molar mass
Number of moles = 4 g/ 2 g/mol
Number of moles = 2 mol
Pressure of dihydrogen:
PV = nRT
P = nRT/V
P = 2 mol × 0.083 bar.dm³ / mol.K × 300 K / 1 dm³
P = 49.8 bar.dm³ /1 dm³
P = 49.8 bar
Total pressure of mixture in a vessel:
Total pressure = P (O₂) + P(H₂)
Total pressure = 6.97 bar + 49.8 bar
Total pressure = 56.77 bar
28. Which of the following statements is TRUE about acids and bases
A. Acids and bases do not react with each other
B Acids mixed with bases neutralize each other
C Acids mixed with bases make stronger bases
D. Acids mixed with bases make stronger acids
hont to flow called?
Answer:
B. Acid mixed with bases neutralize each other
Answer:
Hey buddy, here is your answer. Hope it helps you.
Explanation:
B- Acids mixed with bases neutralize each other. Acid + base ——-> salt+water solution. Mixing these two will make them neutralize .
Can gravity be considered a force?
Answer: Gravity is considered a universal force because it acts between any two masses anywhere in the universe.
Answer:
Gravity (from Latin gravitas 'weight'[1]), or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light[2]—are brought toward (or gravitate toward) one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides.
Clay and Pumice have pores but the pores are not well connected. If you poured water over either of them it would just run off the surface. It wouldn't run through. But they could hold water in their pores. We can say then that both or them ARE ___________________ but NOT __________________________________.
Answer:
Clay and Pumice can both be said to be Porous but they are not Permeable
Explanation:
A porous substance is one which have pores in in through which air or liquid can pass through. Both clay and pumice are porous due to the presence of pores in them. These pores allow air to pass through them. However, since the pores are not well connected water do no pass through them. As a result, clay vessels can hold water within them and pumice floats on water.
Permeability is the ability of a substance to allow other substances to pass through. Both clay and pumice have low permeability, as a result they do not allow water to pass through them. Rather, water runs over their surface when poured over them.
Answer:
Clay and Pumice can both be said to be Porous but they are not Permeable
Explanation:
Which two statements are true about redox reactions?
A. They include both oxidation and reduction reactions,
B. Electrons are transferred.
C. They are double-replacement reactions.
D. They are acid-base reactions,
Answer:
A. They include both oxidation and reduction reactions AND B. Electrons are transferred.
Explanation:
a p e x
The statements that are true about redox reaction are:
A. They include both oxidation and reduction reactions,
B. Electrons are transferred.
What is a redox reaction?The Redox reaction is the one in which oxidation and reduction take place simultaneously. In this process transfer of electrons takes place which further leads to oxidation or reduction.
Thus, options A and B are correct.
Find more information about Redox reaction here:
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