Answer:
45g
Explanation:
Use the Mole = Mass x Mr equation:
Rearrange the above equation to find mass,
Mass = 2.5 moles x 18 (Mr of H₂O) = 45g
Therefore answer is 45g
Answer:
Given
number of moles (n) =2 . 5 mol
R.tc maas of H2O (m) =?
sln
H2O =(1x2+16)
=18g/mol
n=m/mr
m=nxmr
m=2.5x18
m=45g
mass of water is 45g
Hydrogen burns exothermically in oxygen
What is the energy given out during the reaction: 2H2 + O2 -> 2H2O?
Given:
H-H bond: 436 kJ/mol
O=O double bond: 498 kJ/mol
O-H bond: 464 kJ/mol
A. -3226 kJ/mol
B. -884 kJ/mol
C. -486 kJ/mol
D. -442 kJ/mol
Answer:
C. -486 kJ/mol
Explanation:
Enthalpy change equals bonds broken (reactants) minus bonds formed (products)
Bonds broken = 2 H-H bonds + 1 O=O double bond = 2(436) +498 = 1,370 kJ/mol
Bonds formed = 4 O-H bonds = 4(464) = 1,856 kJ/mol
Bonds broken - bonds formed = 1,370 - 1,856 = -486 kJ/mol
What is the basic unit of structure and function in all living things? a cell b organism c atom d plasma
Answer:
A. Cell
Explanation:
Cells are basic units of structure and function in living things. This means that cells form the parts or an organism and carry out all of the an organism's processes, or functions.
A compound contains 53% Al and 47% O by mass. What
is the empirical formula of this compound?
Answer:
Al2O3
Explanation:
Empirical formula is found by converting percent composition into a mole ratio.
First, assume you have a 100g sample of the substance. This allows you to make your percent composition into grams.
100% = 100g
53% = 53g Al
47% = 47g O
Next, divide each substance's mass by their molar mass. This converts your number to moles.
[tex]53g Al / 27g Al = 1.96 mol\\\\47g O/16g O = 2.93mol[/tex]
Next, divide both mol answers by the smallest number of moles.
[tex]1.96mol/1.96mol = 1\\2.93mol/1.96mol = 1.5[/tex]
Usually, these answers would be your subscripts for your empirical formula. However, we cannot have a decimal subscript, so we will multiply our answers by a factor of 2 to get to a whole number. This gives us 2 moles of Al and 3 moles of oxygen, or a formula of Al2O3.
Considering the definition of empirical formula, the correct answer is the second option: the empirical formula is Al₂O₃.
Definition of empirical formulaThe empirical formula is the simplest expression to represent a chemical compound, which indicates the elements that are present and the minimum proportion in whole numbers that exist between its atoms, that is, the subscripts of chemical formulas are reduced to the most integers. small as possible.
Empirical formula in this caseAssuming a 100 grams sample, the percentages match the grams in the sample. So you have 53 grams of Al and 47 grams of O.
Then it is possible to calculate the number of moles of each atom in the molecule, taking into account the corresponding molar mass:
Al: [tex]\frac{53 grams}{27 \frac{grams}{mole} }[/tex]= 1.9629 moles
O: [tex]\frac{47 grams}{16 \frac{grams}{mole} }[/tex]= 2.9375 moles
The empirical formula must be expressed using whole number relationships, for this the numbers of moles are divided by the smallest result of those obtained. In this case:
Al: [tex]\frac{1.9629 moles}{1.9629 moles}[/tex]= 1
O: [tex]\frac{2.9375 moles}{1.9629 moles}[/tex]≅ 1.5
You cannot have a decimal subscript, so you will multiply our answers by a factor of 2 to get to a whole number:
Al: 1× 2= 2
O: 1.5× 2= 3
Therefore the Al:O mole ratio is 2: 3
Finally, the correct answer is the second option: the empirical formula is Al₂O₃.
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What will happen if you heat aliquid to high temperatures?
Answer:
An increase in the temperature of a liquid causes an increase in the average speed of its molecules. As the temperature of a liquid increases, the molecules move faster thereby increasing the liquid's kinetic energy.
If a small pig runs 46 meters in 6 seconds, what is the pig's average speed?
6 m/s
276 m/s
7 m/s
48 m/s
Answer:
the pig's average speed is 7 m/s
The average speed of a moving body is the ratio of the distance travelled to the time of travel. Here, the speed of the pig running 46 meters in 6 seconds is 7.6 m/s.
What is average speed ?The speed of an object is a physical quantity that measures the distance travelled by the object per unit time. Hence, it is the ratio of distance travelled to the time taken for the travel. The rate of speed is called velocity. Bot are having the standard unit of m/s.
Given that,
distance covered by the pig = 46 meters
time taken = 6 seconds
speed = distance/time.
Average speed of the pig = 46 meters/ 6 seconds = 7.6 m/s.
Therefore, if the small pig runs 46 meters in 6 seconds, it is having an average speed of 7.6 m/s.
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When the Sun and Moon are aligned in the same direction, the tides are higher than normal, known as________
Answer:
spring tides is the correct answer of your question
Sally has constructed a concentration cell to measure Ksp for MCln. She constructs the cell by adding 2 mL of 0.05 M M(NO3)n to one compartment of the microwell plate. She then makes a solution of MCln by adding KCl to M(NO3)n. She adds 8.138 mL of the resulting mixture to a second compartment of the microwell plate. Sally knows n (the charge on the metal ion) = +2
She has already calculated [Mn+] in the prepared MCln solution using the Nernst equation. [Mn+] = 8.279 M
Required:
How many moles of [Cl-] must be dissolved in that compartment?
Answer:
0.13475 mol
Explanation:
From this question sally knows that n= 2
MCln = MCl
[Mn+] using nernst equation = 8.279
The volume of the resulting mixture Mn+ = 8.138 ml
The number of moles mn+ =
8.279 x 8.138
= 67.375mmol
= 0.067375
Since n = 2
The mold of cl- that must be dissolved in the compartment
= 0.067375 x 2
= 0.13475 mols
Look at the diagram below.
Ray 1 from the Sun moves through air and falls on the surface of a lake. Ray 2 is a ray which travels from the surface of the lake at the point Ray 1 strikes the lake, and moves towards air. Ray 1 and Ray 2 make the same angle with the surface of the lake. Ray 1 bends towards the vertical when it enters the lake as Ray 3
Which statement is true?
Ray 2 is the refracted ray.
Ray 3 is the reflected ray.
Ray 1 and Ray 2 make the same angle with the vertical line.
Ray 1 and Ray 3 make the same angle with the vertical line.
Answer:
3rd statment
Explanation:
ray 1 and 2 are same vertical line
Answer: C: Ray 1 and Ray 2 make the same angle with the vertical line.
Explanation:
how is a simple cell constructed
Answer:
a simple voltaic cell is made by immersing one zinc plate and one copper plate inside water diluted sulfuric acid solution.
Which pair of elements is most likely to have similar properties? *
Explanation:
Two different elements have similar chemical properties when they have the same number of valence electrons in there outermost energy level. Elements in the same column of the periodic table have similar chemical properties.
A balloon filled with helium has a volume of 30.0 L at a pressure of 100 kPa and a temperature of 15.0°C. What will the volume of the balloon be if the temperature is decreased to -80.0°C and the pressure remains constant?
Answer:
[tex]V_2=20.1L[/tex]
Explanation:
Hello there!
In this case, since this is a problem in which the pressure of the gas remains constant, we can use the Charles' law as a directly proportional relationship between temperature (in Kelvins) and volume given by:
[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]
Thus, solving for the final volume as the temperature is decreased to -80.00 °C, we obtain:
[tex]V_2=\frac{V_1T_2}{T_1}[/tex]
[tex]V_2=\frac{30.0L*(-80+273)K}{(15+273)K} \\\\V_2=20.1L[/tex]
Best regards!
How many grams of oxygen are needed to burn 10.0 moles of C3H8?
How many atoms are in neon
The relative atomic mass of Ne = 20.2. Therefore 20.2 g of neon contains 6.022 × 1023 Ne atoms.
Answer:
I believe 10
Explanation:
if i'm wrong report my answer so it gets deleted and someone else can answer
What is the molarity of ZnCl, that forms when 20.0 g of zinc completely reacts with CuCl2, according to the following reaction? Assume a final
volume of 285 mL
Zn(s) + CuCl2(aq) → ZnCl2(aq) + Cu(s)
Calculate the molarity of a MgSosolution
prepared by adding 0.37 moles of MgSO, to
enough water to make 11 of solution.
Answer in units of V.
Answer:
is
Explanation:
because
If 263 ml of a gas is collected at 47°c and 2.77 atm, what will the final temp be in C if the volume decreases to 195 mL and the pressure increases to 3.87 atm?
im stoopid so yeh pls help
Answer:
[tex]58.48^{\circ}\text{C}[/tex]
Explanation:
[tex]P_1[/tex] = Initial pressure = 2.77 atm
[tex]V_1[/tex] = Initial volume = 263 mL
[tex]T_1[/tex] = Initial temperature = [tex]47^{\circ}\text{C}=(47+273.15)\ \text{K}[/tex]
[tex]P_2[/tex] = Final pressure = 3.87 atm
[tex]V_2[/tex] = Final volume = 197 mL
[tex]T_2[/tex] = Final temperature
We have the relation
[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\Rightarrow T_2=\dfrac{P_2V_2}{P_1V_1}\times T_1\\\Rightarrow T_2=\dfrac{3.87\times 195}{2.77\times 263}\times (47+273.15)\\\Rightarrow T_2=331.63\ \text{K}=331.63-273.15\\\Rightarrow T_2=58.48^{\circ}\text{C}[/tex]
The final temperature will be [tex]58.48^{\circ}\text{C}[/tex].
How much NaCl would you dissolve and dilute to the 100.00 mL mark in a volumetric flask with DI H2O to prepare a 0.825 M sodium chloride solution?
Answer:
4.82 g
Explanation:
To solve this problem we'll use the definition of molarity:
Molarity = moles / litersWe are given the volume and concentration (keep in mind that 100mL=0.100L):
0.825 M = moles / 0.100 LNow we calculate the number of NaCl moles required:
moles = 0.0825 molThen we convert 0.0825 NaCl moles into grams, using its molar mass:
0.0825 mol * 58.44 g/mol = 4.82 gBalance the following equations:
C3H8 (g) + O2 (g) → CO2 (g) + H2O (g)
NH3 (g) O2 (g) NO2 (g) H2O (g)
Al(NO3) Na3S Al2S3 NaNO3
Explanation:
C3H8 + 502 ----> 3CO2 + 4H20
4NH3+7O2------> 4NO2+6H2O
2Al(NO3)3 + 3Na2S -------> Al2S3+6NaNO3
2. Write the symbol proposed by Dalton for silver, sulphur. oxygen and gold.
Answer:
check the pdf hope it helps :)
Explanation:
give the n for the following orbitals
a. 3p
b. 4f
Answer:
a. n = 3
b. n = 4
Explanation:
n is just the number in front of the orbital, as n represents the energy level of the orbital.
Answer:
1. n=3
2.n=4
Explanation:n is the number infront of the orbital that representgsthe energy level
How would you prepare 500 cm3 of 2.0 M solution of Na2CO3 solution from its anhydrous salt? [C = 12, O = 16, Na = 23
Answer:
The answer to your question is given below
Explanation:
We'll begin by converting 500 cm³ to L. This can be obtained as follow:
1000 cm³ = 1 L
Therefore,
500 cm³ = 500 cm³× 1 L / 1000 cm³
500 cm³ = 0.5 L
Next, we shall determine the number of mole of Na₂CO₃ in the solution. This can be obtained as follow:
Volume = 0.5 L
Molarity = 2 M
Mole of Na₂CO₃ =?
Molarity = mole /Volume
2 = Mole of Na₂CO₃ / 0.5
Cross multiply
Mole of Na₂CO₃ = 2 × 0.5
Mole of Na₂CO₃ = 1 mole
Finally, we shall determine the mass of 1 mole of Na₂CO₃. This can be obtained as follow:
Mole of Na₂CO₃ = 1 mole
Molar mass of Na₂CO₃ = (23×2) + 12 + (16×3)
= 46 + 12 + 48
= 106 g/mol
Mass of Na₂CO₃ =?
Mass = mole × molar mass
Mass of Na₂CO₃ = 1 × 106
Mass of Na₂CO₃ = 106 g
Thus, to prepare the solution, weigh 106 g of Na₂CO₃ and dissolve in 500 cm³ (i.e 0.5 L) of water.
Name the type of ion formed by the atom when it loses three electrons. Show by illustration
Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ions or polyatomic atoms. Therefore, Al³⁺ is the type of ion that is formed by the aluminium when it loses three electrons.
What is Ions?Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.
Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral. Al³⁺ is the type of ion that is formed by the aluminium when it loses three electrons.
Therefore, Al³⁺ is the type of ion that is formed by the aluminium when it loses three electrons.
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7) What is the speed of a jet plane
that flies 7200 km in 9.5 hours?
Answer:
68,400
Explanation:
What do melting, evaporation, and sublimation have in common?
Explanation:
Sublimation describes a solid turning directly into a gas. Melting, on the other hand, occurs when a solid turns into a liquid. Water can, under the right circumstances, sublimate, though it usually melts at temperatures above 0 degrees Celsius or 32 degrees Fahrenheit. Carbon dioxide (CO2), however, is very different. The conditions that determine whether CO2 melts or sublimates are both temperature and atmospheric pressure.
Mg(OH)2 is a compound. How many different elements are found in this compound?
Ο Α. 1
ОВ. 3 3
O c. 2
Answer:
3
Explanation:
3 different elements are found
Mg - magnesium
O -oxygen
H - hydrogen
'
mark brainliest
Answer: 3
Explanation:
how does someone get addicted to meth?
Which of the following best describes what happens when an ionic bond forms?
Answer:
Electrons are shared when ionic bonds are formed
The statement which describes an ionic bond formation is " a metal donates one or more of its electron to a non-metal.
What is an ionic bond?An ionic bond is formed between two atoms by electron donating by one atom and gaining by the second atom. The electron donating element is electropositive and the electron accepting one is electronegative.
Normally the electropositive elements are metals of 1st or 2nd group of periodic table. They can make bond with non-metals like halogens and other electronegative elements like nitrogen, oxygen etc.
Therefore, the force of attraction which binds two atoms together in an ionic bond is formed by electron donation by a metal to a non-metal.
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Identify each of the patterns labeled in the ridge pattern diagram
Answer: The suspected and crime scene fingerprint patterns are similar which means they belong to the same individual.
Explanation:
A: Ending ridge between two lines forming a loop like structure common in both suspected and crimes scene patterns.
B: Bifurcation which includes the formation of fork like shape of the ridge.
C: Island is a dot or point like structure which is common in both patterns.
D: It includes delta which is seen in the case of loop and whorl patterns of the fingerprint in loop there is only one delta and in case of whorl there are two deltas. The delta have an island and a bifurcation in it which is common in both patterns of the fingerprints.
E: Intersection occurs when two ridges changes their directions. It is common in the two patterns.
Which best describes why animals need the energy in food?
A for growth and body repair
B for transpiration and growth
C for body repair and photosynthesis
D for cell reproduction and transpiration
Answer:
A for growth and body repair
Explanation:
B, C, and D don't have anything to do with animals.
what prediction can i make about malaria
Answer:
A disease caused by a plasmodium parasite, transmitted by the bite of infected mosquitoes.
The severity of malaria varies based on the species of plasmodium.
Symptoms are chills, fever, and sweating, usually occurring a few weeks after being bitten.
People traveling to areas where malaria is common typically take protective drugs before, during, and after their trip. Treatment includes antimalarial drugs.
Explanation: