Answer:
147 g
Explanation:
The number of moles of a substance is the ratio of the mass of the substance and the molar mass of that substance. Mathematically,
mole = mass of substance/molar mass
In this case, Nick needs 3.5 moles of NaF, the molar mass of NaF is calculated as:
23 + 19 = 42 g/mol (Note: Na = 23, F = 19)
Hence,
mass of 3.5 mole NaF = mole x molar mass
= 3.5 x 42 = 147 g.
Hence, Nick would need to measure out 147 g NaF using a suitable weighing balance.
100
80
100 mL
water vapor
Which statement describes what will happen if a student pushes the plunger
to compress the water vapor?
A. The total number of water particles will increase.
B. The amount of energy in the water particles will decrease.
C. The amount of empty space between the water particles will
decrease
D. The total volume of the water particles will increase
I will mark brainliest
Answer:
Explanation:it is c
Answer:
C The amount of empty space between the water particles will decrease
Explanation:
I just took the quiz, have a nice day!
When [H+] = 4.0 × 10–9 M in water at 25°C, then
Kw =1.0×10–14.
b. pOH = 7.
c. [H3O+] = [OH–].
d. pH= 7
e. A-D are all correct
Answer:
a. Kw = 1.0 × 10⁻¹⁴
Explanation:
a. Let's consider the self-ionization of water.
2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻
The ion-product of water (Kw) at 25 °C is:
Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴
c. Considering [H⁺] = [H₃O⁺] = 4.0 × 10⁻⁹ M, the concentration of OH⁻ is:
[OH⁻] = 1.0 × 10⁻¹⁴/[H₃O⁺] = 2.5 × 10⁻⁶ M
b. We can calculate the pOH using the following expression.
pOH = -log [OH⁻] = -log 2.5 × 10⁻⁶ = 5.6
d. We can calculate the pH using the following expression.
pH = -log [H⁺] = -log 4.0 × 10⁻⁹ = 8.4
When [H+] = 4.0 × 10–9 M in water at 25°C, then the [tex]Kw =1.0\times 10^-^1^4.[/tex]
What is dissociation constant?
Kw is the dissociation constant or ionization constant of water.
The self-ionization of water will be
[tex]\rm 2 H_2O(l) = H_3O^+(aq) + OH^-[/tex]
The dissociation constant of the water at 25°C will be
[tex]\rm Kw = [H_3O^+][OH^-] = 1.0 \times 10^-^1^4[/tex]
Thus, the correct option is a. [tex]Kw =1.0\times 10^-^1^4.[/tex]
Learn more about dissociation constant
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is pure water a solution
Answer: No because a solution is a homogeneous MIXTURE of two or more substances. Water is a pure substance. It is made of hydrogen and oxygen, but shares none of their properties. So it’s pure.
Explanation:
True or False: In general, the farther a location is from the equator, the cooler the climate.
Answer: True
Explanation: The farther away from the center or heat.
Answer:
Yes
Explanation:
The equator is the imaginary belt around the earth and it is created and named because the sun mostly shines on that part/line making heat which causes it to be hot.
Please help with this question..thank you
All of these affect weather except!
A. Air pressure
B. Humidity
C. Barometer
D. Wind speed
Answer:
C.Barometer
Explanation:
A radiometer is shown below. When infrared light passes through the radiometer
7. Which of the following pairs of elements is most likely to form an ionic
compound?
b. potassium and neon
c. barium and aluminum
a. oxygen and fluorine
d. lithium and bromine
Answer:
not sure if this us right but oxygen and fluorine? I learned chem but I forgot about it kinda sorry
How do substances and mixtures diifer
The composition of one is always the same, and the composition of the other varies
One contains only one type of atom, and the other contains two or more
One is always homogeneous, and the other is always heterogeneous
One contains one type of molecule, and the other contains two types
it for 100 points please give it correctly.
Answer:
hello hope this helps :)
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
Two descriptions about physical quantities are given below:
Quantity A: It is a force.
Quantity B: It changes when the object travels from Earth to Earth's moon.
What quantities are these most likely describing?
Select one:
a. Both Quantity A and Quantity B are mass.
b. Both Quantity A and Quantity B are weight.
c. Quantity A is weight and Quantity B is mass.
d. Quantity A is mass and Quantity B is weight.
Answer:
[tex]\huge\boxed{\sf Option \ B}[/tex]
Explanation:
=> Weight is an attractive force which is exerted on any body.
=> It changes when the object's place changes as it depends upon the acceleration due to gravity ( g = 9.8 m/s ) which changes as we move from place to place.
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AnonymousHelper1807Andesitic rock is an igneous rock with a composition in between that of basaltic and granitic igneous rock.
true or false
Answer:
Explanation:
intristing
is chromate polar or nonpolar?
Answer:
i THINK so
Explanation:
im not sure tho sorry if wrong
A 4.03 g sample of nitrogen gas has a volume of 921 milliliters at a pressure of 3.19 atm. The temperature of the N2 gas sample is:_____.
Answer:
249 K
Explanation:
Step 1: Given data
Mass of nitrogen (m): 4.03 gVolume of the gas (V): 921 mL = 0.921 LPressure of the gas (P): 3.19 atmStep 2: Calculate the moles corresponding to 4.03 g of nitrogen
The molar mass of N₂ is 28.01 g/mol.
4.03 g × 1 mol/28.01 g = 0.144 mol
Step 3: Calculate the temperature of the gas sample
We will use the ideal gas equation.
P × V = n × R × T
T = P × V / n × R
T = 3.19 atm × 0.921 L / 0.144 mol × 0.0821 atm.L/mol.K
T = 249 K
How much water would need to be added to 1092 mL of a 54.7 M NaCl solution to make a 0.25 M solution?
Answer:
237.8L of water would need to be added.
Explanation:
The first thing to do is to identify that the equation to be used is M1V1=M2V2. (This equation works because it turns everything into moles which can then be compared).
Then figure out what information you have and what is being found. In this case:
M1 = 54.7 M
V1 = 1092 mL = 1.092 L
M2 = 0.25 M
V2 = unknown
Then solve the equation for whatever you are trying to find.
M1V1=M2V2
V2=M1V1/M2
Now you need to plug everything in.
V2=(54.7M*1.091L)/0.25M
V2=238.93L
That means that the solution needs a volume of 238.7L to gain a molarity of 0.25M but the starting solution already had a volume of 1.092 L meaning that to find the amount of solvent that needs to be added you just subtract the starting volume by the volume that the solution needs to be.
238.93L - 1.091L = 237.8L
Therefore the answer is that 237.8L needs to be added to a 1.092L 54.7M NaCl solution to make the concentration 0.25M.
I hope this helps. Let me know if anything is unclear.
.What does the changing the Aperture do when taking a photo? *
4.What effect can you get from using a slow shutter speed? *
5.What effect can you create by using a quick shutter speed?
Answer:
Slower shutter speeds like 1/60 second and slower cause a blurring effect. If you want to take a picture using a slow shutter speed, it is best to mount the camera on a tripod and use image stabilization (such as SteadyShot® technology) to reduce the chance of any unwanted camera movement.
The first big effect of it is motion blur. If your shutter speed is long, moving subjects in your photo will appear blurred along the direction of motion. ... If you use an especially fast shutter speed, you can eliminate motion even from fast-moving objects, like birds in flight, or cars driving past.
Explanation:
An object that has kinetic energy must be?
A at rest
B stopped
C in motion
Or
D at an elevated position
Answer:
C in motion
Explanation:
trust
why are there different types of matter.
Answer:
solid ; liquid and gas........
Please help me ASAP
How can the image be described? Check all that apply.
smaller than the object
real
right-side up
larger than the object
upside down
virtual
Answer:
Smaller than the object
Real
Upside down
Explanation:
The image formed by a convex lens will always be real and smaller. The image formed is smaller than the object, real ,upside down and right side up. Hence, options 1,2,3 and 5 are correct.
What is convex lens?Convex lens is a type of lens, in which one at least one side is curved outside. These lenses have the ability to focus an outside light beam to a spot on the opposite side by converging it.
The focal length of the convex lens is the distance from the lens's center to this point, which is known as the focus. On the other hand, a plano-convex lens has one surface that is flat and the other that is convex.
Convex lenses cause light from an item to bend, creating an upright, smaller, and inverted picture of the original object. As a result, the candle in this instance will be smaller, upside down, and actual.
Find more on convex lens:
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#SPJ6
NEED HELP ASAP!!
(04.04 LC)
Which statement is true about the products of cellular respiration?
They contain oxygen.
They contain glucose.
They become the products of photosynthesis.
They become the reactants of photosynthesis.
Answer:
They contain oxygen
hope it helps
17 Which changes decrease the rate of reaction between magnesium and air?
1.heating the magnesium to a higher temperature
2.using a higher proportion of oxygen in the air
3.using magnesium ribbon instead of powdered magnesium
A 1, 2 and 3
B 1 only
C 2 only
D 3 only
Using magnesium ribbon instead of powdered magnesium decrease the rate of reaction between magnesium and air.
What is rate of reaction?Rate of reaction tells about the duration of the completion of the reaction.
Rate of any reaction is directly proportional to the concentration and surface area of the reactant, temperature, catalyst, no. of collision, activation energy, etc.
So, if we magnesium in the ribbon instead of powdered magnesium the surface area of the reactant side decreases which results in the decrease of the rate of reaction.
Hence, option (D) is correct i.e. rate of reaction decreases on using magnesium ribbon instead of powdered magnesium.
To know more about rate of reaction, visit the below link:
https://brainly.com/question/1898560
Why is it possible for an active metal like aluminum to be useful as a structural metal?
Answer:
Aluminum even after being an active metal is used as a structural metal due to its toughness, high strength, lightweight, and resistance to the process of corrosion. It is resistant to corrosion as its reactivity gets suppressed due to the formation of an aluminum oxide film which is protective in nature, on its surface. Passivation is the term for the formation of the protective coating.
Which of the following is not a balanced nuclear equation?
O a) 130 Sn + B + 1315b
d) 19Pt → 158 Os+ja
c) Be → 19 Li + AB
b) 2U → 1a +
234
90
Th
Ne
Answer:
¹⁰₄Be —> ¹⁰₃Li + ⁰₋₁β
Explanation:
To know which equation is unbalanced, we shall compare the mass number and atomic number of the reactant and product together. This is illustrated below:
¹²¹₅₀Sn —> ⁰₋₁β + ¹²¹₅₁Sb
121 = 0 + 121
121 = 121
50 = –1 + 51
50 = 51
Thus the above equation is balanced
¹⁹⁰₇₈Pt —> ¹⁸⁶₇₆Os + ⁴₂α
190 = 186 + 4
190 = 190
78 = 76 + 2
78 = 78
Thus, the above equation is balanced
¹⁰₄Be —> ¹⁰₃Li + ⁰₋₁β
10 = 10 + 0
10 = 10
4 = 3 + (–1)
4 = 3 – 1
4 = 2
Thus, the above equation is unbalanced.
²³⁸₉₂U —> ⁴₂α + ²³⁴₉₀Th
238 = 4 + 234
238 = 238
92 = 2 + 90
92 = 92
Thus, the above equation is balanced.
From the illustrations made above, only ¹⁰₄Be —> ¹⁰₃Li + ⁰₋₁β
Is unbalanced.
What is the name for the group of unreactive elements on the periodic table?
Noble Gases, at least that's what I was told. Hope that helps.
What happens when a wire passes through a magnetic field?
Answer:
If a coil of wire is placed in a changing magnetic field, a current will be induced in the wire. This current flows because something is producing an electric field that forces the charges around the wire. (It cannot be the magnetic force since the charges are not initially moving).
Explanation:
Answer:
When a conductor moves through a magnetic field, there will be a generated motional emf. This is one example of Faraday's Law and it arises from the magnetic force. The voltage generated in a length of wire, presuming that the entire length moves through a uniform field, is given below.
Explanation:
To be honest I just googled
The nutrition label shows the total amount of carbohydrates in grams. One gram of carbohydrates provides four calories of energy.
For this food, the number of calories obtained from carbohydrates is
.
Answer:
Dude you need to provide an image because almost everyone is not gonna know what u talkin about.
Explanation:
Describe the process of dimensional analysis and explain why it is so useful in chemical problem solving.
Answer:
Dimensional Analysis (also called Factor-Label Method or the Unit Factor Method) is a problem-solving method that uses the fact that any number or expression can be multiplied by one without changing its value. It is a useful technique.
d Which properties of plastics cause a problem when the container is empty?
Answer: Both of these are of great concern to human health. BPA is used in many things including plastic bottles and food packaging materials. Over time the polymer chains of BPA break down, and can enter the human body in many ways from drinking contaminated water to eating a fish that is exposed to the broken down toxins.
Explanation:
I think you will get it
How many molecules of carbon tetrachloride are equal to 0.25moles
Which equation best represents the balanced net ionic equation for the reaction that occurs when aqueous solutions of lithium phosphate and magnesium nitrate are mixed?
Answer:
2 PO₄³⁻(aq) + 3 Mg²⁺(aq) ⇒ Mg₃(PO₄)₂(s)
Explanation:
Let's consider the molecular equation that occurs when aqueous solutions of lithium phosphate and magnesium nitrate are mixed.
2 Li₃PO₄(aq) + 3 Mg(NO₃)₂(aq) ⇒ 6 LiNO₃(aq) + Mg₃(PO₄)₂(s)
The complete ionic equation includes all the ions and insoluble species.
6 Li⁺(aq) + 2 PO₄³⁻(aq) + 3 Mg²⁺(aq) + 6 NO₃⁻(aq) ⇒ 6 Li⁺(aq) + 6 NO₃⁻(aq) + Mg₃(PO₄)₂(s)
The net ionic equation includes only the ions that participate in the reaction and insoluble species.
2 PO₄³⁻(aq) + 3 Mg²⁺(aq) ⇒ Mg₃(PO₄)₂(s)