Answer:
Explanation:
Using H-H equation for the NaH2O4/Na2HPO4 buffer:
pH = pKa + log [Na2HPO4] / [NaH2PO4]
Where pKa of this buffer is 7.198, [Na2HPO4] = 0.058M = moles [NaH2PO4] = 0.042M = moles
Replacing:
pH = 7.198 + log [0.058M] / [0.042M]
Initial pH = 7.34
Now, NaOH reacts with NaH2PO4 as follows:
NaOH + NaH2PO4 → Na2HPO4 + H2O
That means, the moles of NaOH are additional moles of Na2HPO4 and subtracted moles of NaH2PO4.
The moles of NaOH added:
1.0mm³ = 1.0x10⁻³L * (10mol / L) = 0.01 moles
NaH2PO4:
0.042mol - 0.010mol = 0.032moles
Na2HPO4:
0.058mol + 0.010mol = 0.068moles
Replacing in H-H equation:
pH = 7.198 + log [0.068M] / [0.032M]
Final pH = 7.53
Change in pH = 7.53 - 7.34
The change in pH is 0.19 units
Which of the following wouldn't be a good tool to use when measuring pH values of solutions?
Question 8 options:
a)
litmus paper
b)
digital pH meter
c)
electrical conductivity meter
d)
pH paper
litmus paper
Because it will just tell if the solution is acidic or basic, it won't tell the pH
PLEASE HURRY. compare the reactivitys of potassium and gold metals toward water, what happens when SO2 reacts with water?? write chemical
Answer:
See Explanation
Explanation:
The reactivity of a metal towards water depends on the position of the metal in the electrochemical series. Metals that are high up in the series do react violently and spontaneously with water. Metals that are lower in the series are sometimes unreactive in water.
Hence, potassium reacts very rapidly with water to yield KOH and hydrogen gas while gold does not react with water.
SO2 react with water to form sulphuric acid hence SO2 is called an acid anhydride.
The reaction occurs in the following steps;
2SO2(g) + O2(g) ------->2SO3(g)
SO3(g) + H20(l) ------>H2SO4(aq)
If you want to make 8.00 moles of AlF₃ how many moles of F₂ will you need, using the following balanced chemical equation? 2 Al + 3 F₂ → 2 AlF₃
Answer:
You will need 12.0 moles of F₂
Explanation:
Based on the chemical equation, 2 moles of AlF₃ are produced when 3 moles of F₂ are added in an excess of Al.
Using this expression: 2mol AlF₃ = 3mol F₂ we can find the moles of F₂ as follows:
8.00 mol AlF₃ * (3mol F₂ / 2mol AlF₃) =
You will need 12.0 moles of F₂What is the mass in grams of 1.204 x 1024 molecules of
hydrogen gas (Hz)?
a 14.2 g
b 6.77 g
C 4.03 g
3.45 g
Which is a process that involves collecting information and ideas that are supported by belief or opinion?
science
systematics
pseudoscience
hypothesis
Answer:
The answer is C
Explanation:
I did it on edge
Petroleum is a mixture of hydrocarbons. It is separated into useful fractions by fractional distillation.
Which property does fractional distillation rely on to separate petroleum?
Explanation:
Fractional distillation is used to separate crude oil into simpler, more useful mixtures . This method can be used because different hydrocarbons have different boiling points
Hope this help u
What is the electron configuration of a ground-state Nb2+ ion? Select one: a. 1s22s22p63s23p64s23d104p65s24d1 b. 1s22s22p63s23p64s23d104p64d3 c. 1s22s22p63s23p64s23d104p65s14d2 d. 1s22s22p63s23p64s23d104p64d5 e. 1s22s22p63s23p64s23d104p65s24d3
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. Therefore, the electronic configuration of Nb²⁺ is [Kr]4d³.
What is element?Element generally consist of atoms or we can 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.
The systematic distribution of electrons in the various atomic orbitals is called its electronic configuration. The atomic number of Nb is 41. The electronic configuration of Nb is [Kr] 4d⁴ 5s¹. The electronic configuration of Nb²⁺ is [Kr]4d³. Nb²⁺ also has an odd number of valence electrons. The superscripts represents the number of electrons in each orbitals.
Therefore, the electronic configuration of Nb²⁺ is [Kr]4d³.
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If 20. milliliters of 1.0 M HCl was used to completely neutralize 40. milliliters of an NaOH solution, what was the molarity of the NaOH solution?
A) 0.50 M B) 2.0 M C) 1.5 M D) 4.0 M
Answer:
a)0.50
Explanation:
took one for the team :
How do you maximize the products of chemical reactions?
Answer:
1. increase the temperature
2. increase the concentration of reactants
3. increase the surface area of the reactants
4. use a catalyst
5. remove the product as it's formed
Explanation:
for a chemical reaction to take place, the bonds between atoms in the reactants are broken, the atoms rearrange and new bonds between the atoms are formed to make the products.
Which of the following are physical properties?
Radioactivity
Color
Temperature
Flammability
Texture
Reactivity
Answer:
Explanation:
The properties that are observed or measured without changing the composition of matter are called physical properties.
color, Temperature, Texture are the physical properties as the composition of matter remains the same.
On the other hand, Radioactivity, Flammability and Reactivity comes under chemical property as during the chemical reactions there might be some changes in the properties.
The reaction between solid aluminum and liquid bromine is exothermic. This reaction creates
the product aluminum bromide.
What equation includes the correct formulas and demonstrates conservation of mass?
A Al(s) + Br2(1) - AlBr3(s)
B Al(s) + Br(l) - AlBr(s)
C Al(s) + 3Br(1) - AlBr3(s)
D
2Al(s) + 3Br2(1) - 2AlBr3(s)
Answer:
correct answer is d)
Explanation:
This answer demonstrates law of conservation of mass because the mass of the products is equal to the mass of reactants with the help of the coefficients which is the process known as balancing. This answer also includes the correct formulas, as Br is a gas so it MUST be written as Br2. hope this helps:)
2Al(s) + 3Br2(1) - 2AlBr3(s) is the correct formulas and demonstrates conservation of mass.
What is Conservation of Mass?Every action has an equal and opposite response, states Newton's Third Law. This indicates that any force applied to an item will have an equal and opposite-directed response force of the same magnitude. A force pair is the collective name for these connected forces.
Each individual object will have a different force pair with each other object in systems of numerous objects where all things interact. In the case of charged particles, the charge of each object will dictate the direction of each force in the force pair.
Similar charges will cause particles to repel one another by directing their forces away from one another. With their forces pointing in the same direction, particles with opposing charges attract one another.
Therefore, 2Al(s) + 3Br2(1) - 2AlBr3(s) is the correct formulas and demonstrates conservation of mass.
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solid iron with copper (II) sulfate. Assume the iron will form a +2 charge on the product side. Write the balanced equation for this reaction
Answer:
hey here is the answer to your question.
Explanation:
1) Write a balanced equation for the reaction occurring. (*Iron occurs in a few different oxidation states, but I will assume we're referring to Fe(II) or Fe2+)
Fe + CuSO4 -> Cu + FeSO4
2) Calculate the number of moles of each reactant.
Fe: 1.924 g * (1 mol / 55.85 g) = 0.03455 mol Fe
CuSO4: 0.1363 L * (0.0750 mol / 1 L) = 0.01022 mol CuSO4
3) Determine the limiting reactant. Because we have fewer moles of copper(II) sulfate and are reacting both reactants in a 1:1 ratio, we will run out of copper(II) sulfate first, making it the limiting reactant.
4) Convert moles of the limiting reactant to moles and grams of product of interest.
0.01022 CuSO4 (1 mol Cu / 1 mol CuSO4 ) (63.55 g Cu / 1 mol Cu) = 0.6495 g Cu
7. List all of the variables that you controlled or kept the same.
Salt water
Answer:
Temperature is a common type of controlled variable. If a temperature is held constant during an experiment, it is controlled. Other examples of controlled variables could be an amount of light, using the same type of glassware, constant humidity, or duration of an experiment.
Explanation:
The drawing below was sketched by a student who was observing cells under a microscope. The cell is classified as
A prokaryotic
B eukaryotic
C periodic
D Nucleotic
Answer:
prokaryotic
Explanation:
I got it right
16) What is the acceleration of an object with a mass of 31.5 kg when an unbalanced force
of 223 N is applied to it?
Answer:
a= 7.07 m/s^2
Explanation:
Newton's second law of motion states that the acceleration of an object is produced by the net force.
the formula to calculate the force: F=ma
you just rearrange it to solve for a
a= F/m a=223/31.5
=7.07
Drain Cleaner has an pH of 11. What is its pOH?
Answer:
To find the pOH, simply subtract the pH from 14. In order to calculate the pOH, take the negative log of the hydroxide ion concentration.
Explanation:
Hope this helps :3
So3+H2o→H2 So4
use the oxidation numbers to identify the nature of this reaction redox or not
This is not an redox reaction because the oxidation number of Oxygen atom is not changing.
how do I calculate the density
Four balls have the same temperature. Which ball has the most Thermal Energy? A.Golf ball(45g) B.Basket ball(625g) C.Bowling ball(5000g) D.Tennis ball(60g)
Answer:
b
Explanation:
b. ,u play with the ball, handle the ball grab the ball throw the ball exc.
2AgNO3 (aq) + BaCl2 (aq)
-->
2AgCl (s) + Ba(NO3)2 (aq)
2AgCl (s) + Ba(NO3)2 (aq)
Find the hydroxide ion concentration [OH-] of an HCl solution with a pH of 6.93.
Answer:
[OH-] = 1.8 x 10^-7
Explanation:
pH + pOH = 14 --> 6.93 + pOH = 14 *subtract 6.93 from both sides
pOH = 7.07
-->
10^pH => 10^-6.93 => 1e - 6.93 [H+]
-->
H+ x OH- = 1 x 10^-6.93 *divide H+ from both sides
-->
[OH-] = 1.17 x 10^-7 or 1.8 x 10^-7
Calculate the volume (liters) of solution that can be prepared from 180. grams of K2Cr2O7 for a 0.200M solution.
Answer:
The volume of the solution is 0.305 liters.
Explanation:
Molar mass is the amount of mass that a substance contains in one mole. The molar mass of K₂Cr₂O₇ is 294 g / mole. Then you can apply the following rule of three: if by definition of molar mass 294 grams of the compound are contained in 1 mole, 180 grams are contained in how many moles?
[tex]moles=\frac{180 grams*1mole}{294 grams}[/tex]
moles= 0.61
Molarity is a measure of the concentration of a substance that is defined as the number of moles contained in a certain volume. So, the molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]molarity=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
In this case:
molarity= 2 Mnumber of moles of solute= 0.61 molesvolume= ?Replacing in the definition of molarity:
[tex]2 M=\frac{0.61 moles}{volume}[/tex]
Solving:
[tex]volume=\frac{0.61 moles}{2 M}[/tex]
volume= 0.305 liters
The volume of the solution is 0.305 liters.
what is the pH of the 1.0 M KOH solution?
Answer:
So... pH of the 1.0" 10-2 mol-1 KOH is.. = 12What is the difference between light photons and infrared photons?
Answer:
Light Photons: Light behaves mainly like a wave but it can also be considered to consist of tiny packages of energy called photons. Photons carry a fixed amount of energy but have no mass. The energy of a photon depends on its wavelength: longer wavelength photons have less energy and shorter wavelength photons have more.
Infrared photons: Infrared waves, or infrared light, are part of the electromagnetic spectrum. People encounter Infrared waves every day; the human eye cannot see it, but humans can detect it as heat. A remote control uses light waves just beyond the visible spectrum of light—infrared light waves—to change channels on your TV.
On the electromagnetic spectrum, visible light has a wavelength that falls between 380 nm and 750 nm, whereas infrared light, which marks the beginning of the non-visible spectrum, has a wavelength that falls between 700 nm and 1 mm. Because of this, infrared can only be viewed with specialized tools like security cameras.
What is infrared light ?A type of radiant energy that we experience as heat, but that is invisible to human eyes is infrared radiation (IR), often known as infrared light. The sun and fire are two of the most prominent sources of IR radiation, however all objects in the cosmos release some of it.
The energy of the photons determines the various types of radiation, starting with radio waves with low energies. In comparison to visible, ultraviolet, X-ray, and gamma ray photons, which are the most energetic of all, microwave photons have somewhat higher energy. Infrared photons have even more energy.
Cooler objects produce lower energy, longer wavelength photons, while hotter ones release higher energy, shorter wavelength photons.
Thus, On the electromagnetic spectrum, visible light has a wavelength that falls between 380 nm and 750 nm, whereas infrared light.
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What two things combine with oxygen to form ground-level ozone?
A) NOx and ODS
B) CFCs and halons
C) NOx and VOC
D) HFCs and HCFCs
Answer:
c) NOx and VOC
oxides of nitrogen (NOx) and volatile organic compounds (VOC)
Explanation:
-
im I wrong on this question?
Answer:
I don't think so
Explanation:
That's what I got
All atoms of a given element must contain the same number of
A) protons
B) neutrons
C) electrons plus neutrons
D) protons plus neutrons
-Carbon and Oxygen combine to from carbon dioxide
Answer:
Carbon and oxygen combine to form two oxides, carbon monoxide and carbon dioxide in which the ratio of the weights of carbon and oxygen is respectively 12:16 and 12:32.
what has changed in the atmosphere that give the rock strata the appearance of rust?(red/orange color).
Answer:
Explained below.
Explanation:
What has changed in the atmosphere is that oxidation has occurred where an oxidizing chemical specie has reacted with an oxygen containing compound.
Now these chemicals when they react with rain and fall on rocks react with the rocks to weaken them in a process known as chemical weathering.
Now when this weathering from the oxidizing chemicals from the rain react with rocks that contain iron, it leads to the rock having an appearance of rust.
A group of 6th-grade students constructs arguments on why water conservation is important. Which student argument is correct?
A.
Student 1 argues that people need water for recreation and transportation only.
B.
Student 2 argues that as the population increases in the world, so does the need for water.
C.
Student 4 argues that we use less water for agriculture and more on personal needs.
D.
Student 3 argues that there is an unlimited supply of water for animals, ecosystems, and people to use daily.
From a chemicals standpoint, Student 2 contends that as global population grows, so does the need for water. This is the correct reasoning.
What is the purpose of chemistry?
Our basic needs of food, clothes, shelter, health, energy, and pure air, water, and soil are all met by chemistry. Chemical technologies improve our quality of life in many ways by offering fresh approaches to issues with health, resources, and energy use.
What subjects are studied in chemistry?
The study of matter, including its properties, behaviours, and structures, is known as chemistry. Chemists induce and monitor these reactions both in nature and artificially in a lab setting because they are interested in how materials behave and react in specific settings.
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