Which of these is NOT an example of how your community uses natural
resources?
50cm3 of sodium hydroxide solution was titrated against a solution of sulfuric acid. The concentration of the sodium hydroxide solution was 20g/dm3. Work out the concentration of the acid in grams per litre if it took 25cm3 of acid to completely neutralise the alkali. The relative molecular mass of sulfuric acid is 98.
Answer:
49 g/L is the concentration of the acid
Explanation:
Firstly, we proceed to write the equation of reaction.
2NaOH + H2SO4 ——-> Na2SO4 + 2H2O
We can see that 1 mole of the base reacted with two moles of the acid.
kindly note that dm^3 is same as liter
Firstly, we need to get the concentration of the reacted sulphuric acid in g/L
we use the simple titration equation below;
CaVa/CbVb = Na/Nb
From the question;
Ca = ?
Va = 25 cm^3
Cb = 20 g/L
we convert this to concentration in mol/L
Mathematically, that is concentration in g/L divided by molar mass in g/mole
molar mass of NaOH = 40 g/mol
so we have; 20g/L / 40 = 0.5 mol/L
Vb = 50 cm^3
Na = 1
Nb = 2
Where C represents concentrations, V volumes and N , number of moles
Now, substitute the values;
Ca * 25/0.5 * 50 = 1/2
25Ca/25 = 0.5
So Ca = 0.5 mol/L
Now to get the concentration of H2SO4 in g/L
What we do is to multiply the concentration in mol/L by molar mass in g/mol
That would be 0.5 * 98 = 49 g/L
The concentration of the acid in grams per litre is 49g/L
From the question,
We are to determine concentration of the sodium hydroxide solution.
First, we will write a balanced chemical equation for the reaction.
The balanced chemical equation for the reaction is
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
This means,
2 moles of NaOH is required to completely neutralize 1 mole of H₂SO₄
From the formula
[tex]\frac{C_{A}V_{A} }{C_{B}V_{B} }=\frac{n_{A} }{n_{B} }[/tex]
Where
[tex]C_{A}[/tex] is the concentration of acid
[tex]C_{B}[/tex] is the concentration of base
[tex]V_{A}[/tex] is the volume of acid
[tex]V_{B}[/tex] is the volume of base
[tex]n_{A}[/tex] is the mole ratio of acid
[tex]n_{B}[/tex] is the mole ratio of base
From the question
[tex]V_{A}= 25 \ cm^{3}[/tex]
[tex]C_{B} = 20 \ g/dm^{3}[/tex]
Convert this to mol/dm³
Molar mass of NaOH = 40 g/mol
Using the formula
[tex]Concentration\ in \ mol/dm^{3} =\frac{Concentration\ in \ g/dm^{3}}{Molar\ mass}[/tex]
∴ Concentration of the NaOH in mol/dm³ = [tex]\frac{20}{40}[/tex]
Concentration of the NaOH in mol/dm³ = 0.5 mol/dm³
∴ [tex]C_{B} = 0.5 \ mol/dm^{3}[/tex]
and
[tex]V_{B} = 50 \ cm^{3}[/tex]
From the balanced chemical equation
[tex]n_{A} = 1[/tex]
[tex]n_{B} = 2[/tex]
Putting the parameters into the formula, we get
[tex]\frac{C_{A} \times 25}{0.5 \times 50}= \frac{1}{2}[/tex]
Now, this becomes
[tex]2 \times 25 \times C_{A}=0.5 \times 50 \times 1[/tex]
Then, we get
[tex]50 C_{A} = 25[/tex]
∴ [tex]C_{A} = \frac{25}{50}[/tex]
[tex]C_{A} = 0.5 \ mol/dm^{3} = 0.5 \ mol/L[/tex]
Now, we will determine the concentration in g/L
From the formula,
Concentration in g/L = Concentration in mol/L × Molar mass
From the question,
Molar mass of sulfuric acid = 98
∴ Concentration of the acid in g/L = 0.5 × 98
Concentration of the acid in g/L = 49 g/L
Hence, the concentration of the acid in grams per litre is 49g/L
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What is the definition of acid ?
WILL MARK BRAINLIEST (if the answer is good and hasn't been copied from google and the first one who answer the question )
Answer:
Acid is a compound which dissolves in water to produce hydrogen ions (H+) and described as proton donors.
Element X is a solid that is brittle, lacks luster,and has six valence electrons. In which group on the Periodic Table would element X be found
Answer:
Sulfur?
Explanation:
Sulfur has 6 valence electrons and does not have luster.
The name given to the substance formed when a liquid is miscible in another liquid.
Answer:
Solute
Explanation:
Why would it be more comfortable to walk on hot beach sand in flip-flops
than without them?
O A. Thermal insulation is blocked by the flip-flops.
B. Convection warming is blocked by the flip-flops.
C. Radiation warming is blocked by the flip-flops.
O D. Thermal conduction is blocked by the flip-flops.
Answer:
D. Thermal conduction is blocked by the flip-flops.
Explanation:
Convection is a process of heat transfer which involves fluids( liquid or gas). This however rules convection out of the answer.
Radiation involves heat transfer from the sun to bodies on earth.
Conduction involves heat transfer between two solid bodies. Hot beach sand and flip-flops are solid bodies which validates thermal(heat) conduction.
The pressure inside of a sealed tube if you raise the temperature go ______..
Answer:
The pressure will increase due ot expnasion of gasses in a closed sealed tube tube .
Explanation:
Answer:
The pressure inside of a sealed tube will increase if the temperature is raised.
Explanation:
When the temperature of the gas inside the sealed tube is raised, the particles within that tube will start to become faster and faster. Because they are going faster they collide with the sides of the tube faster, therefore increasing the pressure inside the sealed tube.
Hope this helps!
Elements that form ionic bonds generally have how many valence electrons?
Answer:
they should have a number that can completely transfer and fill the other atom
Explanation:
example:
sodium(2.8.1)and Chlorine(2.8.7)the sodium will give chlorine the 1 valence electrobo so they both become stable(2.8)±and(2.8.8)–
magnesium(2.8.2)and oxygen(2.6)same way as above to abtain mg(2.8)±²and oxygen(2.8)–²
the kidneys in human beings are a part of the system for
2. Which change in oxidation number indicates
oxidation?
A) -1 to +2
C) -1 to - 2
B) +3 to +2
D) +2 to -3
Answer:
A)
Explanation:
Increasing of oxidation number shows that the process is oxidation(or losing of electrons).
-1 to +2, oxidation number is increased. This is an oxidation process.
-
56. What would be the valence electrons of 14Si, 16S, 32Ge respectively?
A. 4, 2,2
B. 4, 6,8
C. 4, 6,6
D. 4,6,4
Answer: D. 4,6,4
Explanation:
The valence electron is the electron found in the outermost shell of an atom, and participates in bond formation.
For the following element, the valence electron can be noticed when we write the electronic configuration of each element.
Silicon = 1s2 2s2 2P6 3s2 3p2
Sulphur = 1s2 2s2 2P6 3s2 3p4
Germanium = 1s2 2s2 2P6 3s2 3p6 3d10 4s2 4p2
For which purpose do biochemist insert human genes into bacteria
Answer: to find a cure for the common cold to produce insulin for diabetics
Explanation: It has helped many people
1). Calculate the mass of hydrogen peroxide needed to obtain 0.460 L of oxygen gas at STP
2H2O2(aq) → 2H2O(l) + O2(g)
2) 1. Use the reaction shown to calculate the mass of iron that must be used to obtain 0.500 L of hydrogen at STP.
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Answer:
1) 1.39 grams H2O2
2) 0.933 grams Fe
Explanation:
Step 1: Data given
Volume of oxygen = 0.460 L
STP = 1 atm and 273 K
Step 2: The balanced equation
2H2O2(aq) → 2H2O(l) + O2(g)
Step 3: Calculate the number of moles O2
p*V = n*R*T
⇒with p= the pressure = 1 atm
⇒with V = the volume = 0.460 L
⇒with n = the number of moles = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 273 K
n = (p*V)/(R*T)
n = (1 * 0.460)/ (0.08206*273)
n = 0.0205 moles moles
Step 4: Calculate moles H2O2
For 2 moles H2O we'll have 2 moles H2O and 1 mol O2
For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2
Step 5: Calculate mass H2O2
Mass H2O2 = moles H2O2 * molar mass H2O2
Mass H2O2 = 0.041 moles * 34.01 g/mol
Mass H2O2 = 1.39 grams
Step 1: Data given
Volume of hydrogen = 0.500 L
STP = 1 atm and 273 K
Step 2: The balanced equation
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Step 3: Calculate the moles of H2
p**V = n*R*T
⇒with p= the pressure = 1 atm
⇒with V = the volume = 0.500 L
⇒with n = the number of moles = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 273 K
n = (p*V) / '*T)
n = (1 * 0.500) / (0.08206 * 273)
n = 0.0223 moles
Step 4: Calculate moles Fe
For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2
For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe
Step 5: Calculate mass of Fe
Mass Fe = moles Fe * atomic mass Fe
Mass Fe = 0.0167 moles * 55.845 g/mol
Mass Fe = 0.933 grams Fe
1. The mass of the hydrogen peroxide should be 1.39 grams H2O2.
2) The mass of the iron should be 0.933 grams Fe.
Calculation of the mass:Since
Volume of oxygen = 0.460 L
STP = 1 atm and 273 K
Now The balanced equation
2H2O2(aq) → 2H2O(l) + O2(g)
Now the number of moles O2
p*V = n*R*T
Here p= the pressure = 1 atm
V = the volume = 0.460 L
n = the number of moles = ?
R = the gas constant = 0.08206 L*atm/mol*K
T = the temperature = 273 K
Now
n = (p*V)/(R*T)
n = (1 * 0.460)/ (0.08206*273)
n = 0.0205 moles moles
Now moles H2O2 should be
For 2 moles H2O we'll have 2 moles H2O and 1 mol O2
So,
For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2
Now mass H2O2
Mass H2O2 = moles H2O2 * molar mass H2O2
Mass H2O2 = 0.041 moles * 34.01 g/mol
Mass H2O2 = 1.39 grams
2. The mass of the iron should be
Since
Volume of hydrogen = 0.500 L
STP = 1 atm and 273 K
Now
The balanced equation
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Now the moles of H2
p**V = n*R*T
Here
p= the pressure = 1 atm
V = the volume = 0.500 L
n = the number of moles = ?
R = the gas constant = 0.08206 L*atm/mol*K
T = the temperature = 273 K
So,
n = (p*V) / '*T)
n = (1 * 0.500) / (0.08206 * 273)
n = 0.0223 moles
Now Calculate moles Fe
For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2
So,
For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe
Now the mass of Fe
Mass Fe = moles Fe * atomic mass Fe
Mass Fe = 0.0167 moles * 55.845 g/mol
Mass Fe = 0.933 grams Fe
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Please can someone help I will mark brainiest!
Answer:
2Cl- ⇒ Cl ↓2+ 2e
Explanation: sorry if this is not what you were looking for.
Kinetic energy definition
Answer:
kinetic energy. (General Physics) the energy of motion of a body, equal to the work it would do if it were brought to rest. The translational kinetic energy depends on motion through space, and for a rigid body of constant mass is equal to the product of half the mass times the square of the speed.
Answer:it is the simplest one
the energy possessed by a body due to its motion is called kinetic energy
K.E.=[tex]\frac{1}{2}[/tex]mv²
what is the difference between cells, tissues and organs
Answer:
A group of cells working together is defined as a tissue and several tissues working together comprise an organ.
Explanation:
Reply ASAP: Why do electrons affect the structure of a molecule?
A. Bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.
B. They do not.
C. The electron clouds are negatively charged and repel each other as far apart as possible.
D. Bonding pairs are negatively charged and lone pairs are positively charged and they push each other into certain shapes.
Answer:
C. The electron clouds are negatively charged and repel each other as far apart as possible
Explanation:
This is the basis of VSEPR theory.
The angles between the electron clouds determine the shapes of the molecules.
B. and D. are wrong. All electron pairs are negatively charged.
The electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.
What is the shape of an atom?Every atom or molecule consist some kind of geometry or shapes like linier, tetrahedral, square planner, octahedral etc. with some bond length and angles present with them.
The bond pairs in a geometry is made up with positive charge and lone pairs present on the atom in the form of negative charge as they both are opposite in nature and repel or push each other in opposite direction.
Due to this phenomena the structure of the atom gets effected and geometry will change on the basis of lone pair and bond pair repulsion.
Therefore, electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.
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I NEED HELP PLEASE, THANKS! :)
Combustion reactions are a notable source of carbon dioxide in the environment. Using the following balanced equation, how many grams of carbon dioxide are formed when 100.00 g of propane (C3H8) is burned? Express your answer to the correct number of significant figures.
Answer:
[tex]\large \boxed{\text{299.4 g}}[/tex]
Explanation:
We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.
Mᵣ: 44.10 44.01
C₃H₈ + 5O₂ ⟶ 3CO₂ + 4H₂O
m/g: 100.00
To solve a stoichiometry problem, you must
Use the molar mass to convert mass of C₃H₈ to moles of C₃H₈ Use the molar ratio to convert moles of C₃H₈ to moles of CO₂ Use the molar mass to convert moles of CO₂ to mass of CO₂
1. Moles of C₃H₈
[tex]\text{Moles of C$_{3}$H}_{8} = \text{100.00 g C$_{3}$H}_{8} \times \dfrac{\text{1 mol C$_{3}$H}_{8}}{\text{44.10 g C$_{3}$H}_{8}} = \text{2.268 mol C$_{3}$H}_{8}[/tex]
2. Moles of CO₂
The molar ratio is 3 mol CO₂:1 mol C₃H₈
[tex]\text{Moles of CO}_{2} = \text{2.268 mol C$_{3}$H}_{8} \times \dfrac{\text{3 mol CO}_{2}}{\text{1 mol C$_{3}$H}_{8}} = \text{6.803 mol CO}_{2}[/tex]
3. Mass of CO₂
[tex]\text{Mass of CO}_{2} = \text{6.803 mol CO}_{2} \times \dfrac{\text{44.01 g CO}_{2}}{\text{1 mol CO}_{2}} = \textbf{299.4 g CO}_{2}\\\text{The mass of CO$_{2}$ required is $\large \boxed{\textbf{299.4 g}}$}[/tex]
Answer:
Number of moles of propane:
=Mass in grams ÷ Relative molecular Mass
= 100/((12*3) + (1*8))
= 100 ÷ 44
= 2.2727
Mole ratio propane:carbon (IV) oxide = 1:3(from the equation)
Number of moles of CO2 = 3*2.2727 = 6.8181
Mass in grams = Relative molecular Mass * Number of moles
= 44 * 6.8181
= 299.9964 grams
Explanation:
the particles with a negative charge are
1) protons
2)neutrons
3)electrons
Answer:
the particles with a negative charge are protons
Energy is the ability to do work or produce heat.
True
False
Answer: true
Explanation: hope this helpes
Answer:
TRUE
Explanation:
power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines.
What volume will be occupied by 11.7 g of Helium in a balloon at an altitude of 10.0 km if the air pressure is 0.262 atm and the temperature is -50.0 °C?
Answer: 204 L
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 0.262 atm
V = Volume of gas = ?
n = number of moles = [tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{11.7g}{4g/mol}=2.92[/tex]
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]-50^0C=(273+(-50))K=223K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{2.92\times 0.0820 L atm/K mol\times 223K}{0.262atm}=204L[/tex]
Thus volume occupied by 11.7 g of Helium in a balloon is 204L
A car travelling at 20km per hour emits about 0.0750kg of carbon monoxide per kilometre. How many mole of carbon monoxide are emitted per kilometre under these conditions?
Answer:
2.67761514 moles
Explanation:
0.075kg equates to 75g.
This means that the car emits 75g of CO per km.
dividing 75g by the molar mass of CO (28.01g/mol) we get 2.67761514 moles
Select True or False: Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.
Answer:
True
Explanation:
Because Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.
Seleccione una actividad humana y el impacto generado debe realizar un resumen sobre la actividad seleccionada y dos medidas de prevención para evitar la alteración de los ciclos.
Answer:
Industrial activity increases the emission of greenhouse gases in the atmosphere, especially carbon dioxide (CO2), and it negatively affects climate by increasing global warming.
Two actions to face the global warming:
1- To substitute the use of fossil fuels by alternative clean energy sources such as, for example, hydroelectric, geothermal, solar and wind energy resources.
2- The government's policies decided to develop electric cars and to stimulate healthy habits such as walking instead of the use of conventional fossil-fueled transport modes.
What does the VSEPR theory predict?
A. The chemical formula of a molecule
B. The size of a molecule
C. The shape of a molecule
D. The charge of a molecule
Answer: C
Explanation:
A P E X
The VSEPR theory predicts the shape and molecular geometry of the molecule.
What is molecular geometry?Molecular geometry can be defined as a three -dimensional arrangement of atoms which constitute the molecule.It includes parameters like bond length,bond angle and torsional angles.
It influences many properties of molecules like reactivity,polarity color,magnetism .The molecular geometry can be determined by various spectroscopic methods and diffraction methods , some of which are infrared,microwave and Raman spectroscopy.
They provide information about geometry by taking into considerations the vibrational and rotational absorbance of a substance.Neutron and electron diffraction techniques provide information about the distance between nuclei and electron density.
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Which of the following statements is true? Less rain and snow falls in smoky areas than in other areas. Acid rain causes corrision of buildings and statues. The first laws againts pollution were passed in the 1990s. Cars are the leading cause of nitrogen oxide pollution.
Answer:
Acid rain causes corrosion in buildings.
Explanation:
This is true because acid rain over time can eat away at the building.
Diagrams, tables, and graphs are used by scientists to
Answer:
Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information • Graphs are created from data tables • hope that helps love!
What does the period number tell about the energy levels occupied by electrons in an atom?
Answer:
Number of energy levels that the element has.
Explanation:
The period number (n) is the outer energy level that is occupied by electrons. The period number that an element is in, is the number of energy levels that the element has.
Visit the interactive periodic table and locate the element neon (Ne). Use the information within the square to answer these questions.
Answer:
What is the atomic number of neon?
10
What is the atomic mass of neon? Give your answer to the nearest tenth.
20.2
The periodic table is a representation of the periodic elements based on atomic numbers. The atomic number of neon is 10, and the atomic mass is 20.2 amu.
What are the properties of neon?Neon is categorized as a stable gas that belongs to the noble gas group. It has been represented as Ne and is a monoatomic gas with no odor or color. It has an atomic number of 10 and an electronic configuration as, [He] 2s²2p⁶.
The atomic mass of neon elements is 20.2 amu and is said to have full electrons per shell. They do not need to donate or accept any electron as they have a balanced orbital. They have the property of fluorescence and are used in electric signs and lamps.
Therefore, neon is placed in group 18 and has atomic number 10 and a mass of 20.2 amu.
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Which compound contains both sigma and pi bonds