Answer:
b
Explanation:
Answer:
B) 4,1,2,3
Explanation:
Did it on USA Test prep. :)
how many Na atomd are shown in the reactants
Answer:
On the reactant side, there are two H atoms and two O atoms
Which statement correctly describes electrochemical cells?
A. Electrochemical cells involve only oxidation reactions.
B. Electrochemical cells involve only reduction reactions.
C. Electrochemical cells involve oxidation-reduction reactions.
D. Electrochemical cells do not involve oxidation-reduction reactions.
Answer: C. Electrochemical cells involve oxidation-reduction reactions.
Explanation: Oxidation occurs at the anode, and reduction occurs at the cathode.
The equation A+ BX à AX + B is the general equation for a
Answer: d
Explanation:
took the test
Plants and animals need to protect themselves to survive. Select the statement that best describes the adaptions of animals and plants.
Which body system includes the heart?
whats the most effective way to study when your teachers dont tell you about a test until the day before the test.? help! currently struggling
Explanation:
You should read the most important questions properly and you should look your syllabus of test.
You should read old questions of test
that were already asked.
A 20.0 mL of 0.27 M solution of the salt NaA has a pH of 8.70.
a) Calculate the pk, value of the acid HA.
(Correct to 3 sig. fig)
b) Calculate the pH of a solution containing 0.3 M HA and 0.1 M NaA.
(Correct to 3 sig. fig)
Thanks!!
Answer:
a) 3.969
b) 3.487
Explanation:
Given data:
m = 0.27 M
pH = 8.7
a) Calculate PKa of acid HA
pH value = 1/2 ( Pkw + Pka + log C )
8.7 * 2 = 14 + log C + Pka
17.4 = 14 + log ( 0.27 ) + Pka
∴Pka = 17.4 - 14.5686 = 3.9686 ≈ 3.969
b) Calculate the pH of solution
pH = pKa + log ( salt / acid )
= 3.9686 + log ( 0.1 / 0.3 )
= 3.487
Which one of the following compounds is insoluble in water?
a) Na2CO3
b) K2SO4
c) Fe(NO3)3
d) ZnS
Answer: ZnS
Explanation: usually salts of alkali metals are well soluble in water.
Also most nitrates are well soluble.
Sulfides of transition metals are generally insoluble in water
Zinc sulfide is a compound which is insoluble in water as it is a sulfide salt of transition metal which are water-insoluble.
What is a compound ?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
Learn more about compounds,here:
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A sample of neon gas is at a temperature of 60°C and has a volume of 300 cm. What is the volume of the gas if it is heated to 100°C at a constant pressure?
Answer:
336.04 cm
Explanation:
T1 = 60+273 = 333K
T2 = 100+273 = 373K
V2 = (V1×T2)/T1
V2 = 300×373/333
V2 = 336.04 cm
Is a 3.3% solution dilute or concentrated?
Dilute
Concentrated
Answer:
Dilute
Explanation:
A concentrated solutions is a one which has relatively large amount of dissolved solute in the solution whereas a dilute solution is a one which has relatively lower concentration of dissolved solute.
In the given solution there is only 3.3% of solute. So, we can say that the given solution is a dilute solution. However, these terms are relative.
The inner wall of the trachea is lined with ciliated mucous membrane loaded full with what?
Answer:
the trachea is full of cilia
HELP!! 30 POINTS!!!! What does the energy graph look like for this reaction??
C3H8+5O2 -> 3CO2+4H2O
I have the data, I just need to know how to make the graph, please!!
total enthalpy of reactants= -103.85
total enthalpy of products= =-2147.81
=-2043.96 kJ/mol exothermic reaction
Answer:
Bottle Nose Dolphin ummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Explanation:
can someone pls help me answer e-j given the instructions above, thank youu
Answer:
e. Not balanced C and O
f. Balanced
g. Balanced
h. Unbalanced Al and O
i. Balanced
j. Balanced
Second part
a. 2
b. 2 and 2
c. For O is 5 while H20 is 4
Explanation:
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HELP MY FRIEND NEEDS HELP WITH THIS!!!!!!
can somebody please help? I'm asking for a friend
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?
Answer:
Oh hey sorry, they deleted my account again..
Explanation:
You are on vacation with your family up in the mountains. Your friend is on vacation near the equator by the ocean. Explain which climate will experience the most precipitation.
A.) Both climates will have the same amount of precipitation.
B.)The ocean climate will have less precipitation because it is close to sea level.
C.)The climate around the equator will have more precipitation because it is very hot.
D.)The mountain climate will have more precipitation because it increases with elevation.
Answer:
I gonna go wit number C
Explanation:
Answer: C
Explanation:
Perform the following
mathematical operation, and
report the answer to the correct
number of significant figures.
3.47 x 6.7 = [?]
Answer:
[tex]3.4 \times 6.7 = 23.249[/tex]
Answer:
23.25
Explanation:
3.47x6.7= 23.249= 23.25 / 23.
In a solution, litmus is blue. The pH of the solution could be
1 10 2 2 3 3 4 4
Answer:
absotutately right
Explanation:
What is the pH color scale?
The pH scale runs from 0 to 14, with each number assigned a different color. At the bottom of the scale sits red, which represents the most acidic, and a dark blue at its opposite end represents 14 and alkalinity. In the middle zone, the pH scale becomes neutral
The pH of the solution could be 10. The basic solution has a pH value of more than 7.
What is pH?pH is a measure of acidity and basicity of aqueous solution.The range of pH goes from 0 - 14, with 7 being neutral.pH of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.pH is the measure of the relative amount of free hydrogen and hydroxyl ions in aqueous or other solutions.Litmus paper helps us qualitatively determine a substance as an acid or base. For any substance to be a base, blue litmus must remain blue.
The pH scale ranges from 0 to 14 and anything below 7.0 is acidic and anything above 7.0 is alkaline or basic.
To learn more about pH here
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PLEASE HELPPPPPPPP
Why do organic materials decompose so slowly inside of a landfill? List 3 factorsthat are required for biodegradation
Answer:
3 factors that are required for biodegradation are
a) Appropriate moisture
b) Oxygen supply
c) Stable condition
Explanation:
For biodegradation in a landfill, following conditions are essential –
a) Appropriate moisture
b) Oxygen supply
c) Stable condition
Contrast to above three conditions, the waste in landfill is kept dry, devoid of oxygen supply, and stirred continuously due to which the organic matter mummify instead of decomposing.
Which of the following compounds, sodium bicarbonate or water, should be used to extinguish a grease fire?
Answer:Douse the fire with baking soda: The chemical compound sodium bicarbonate, commonly called baking soda, is effective for extinguishing this type of fire. It takes a lot of baking soda to smother a grease fire, so pour it on while the flames are still small for the greatest effect
Explanation:
The grease fire has been put down by the addition of sodium bicarbonate as the extinguisher.
Grease fire has been defined as the fire that has been started with the over heating of the cooking oil at home. The fire has been started with the burning of the flammable liquids.
Extinguishing Grease fireThe fire in the cooking oil has been controlled with the addition of the sheet over the fire and turning off the flame.
The addition of water to grease fire results in the splashing of water over the fire and the spreading, resulting in the hazardous effects.
The sodium bicarbonate or baking soda has been used to put down grease fire.
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How could a scientist use a sedimentary rock to provide evidence that the right k cycle is a valid scientific model
Answer:
By closely observing the sedimentary rock and the presence of organic materials and mineral grains in sedimentary rocks
Explanation:
The rock cycle explains how the three types of rock are formed over time from each other.
To use a sedimentary rock to prove that the rock cycle is a valid scientific model is by, closely observing the sedimentary rock. when the sedimentary rock is closed observed the principle of superposition will be seen ( i.e. younger segments deposited on top ), the presence of organic materials and mineral grains that can be found in Igneous or Metamorphic rocks can also be seen and this shows that Sedimentary rocks pass through the rock cycle. hence this proves that the rock cycle is a valid scientific model overtime
hi how do u determine the mass of NaCl [i'm not talking about the molar mass and also pls don't send links to this question]
The covalent bonds in an oxygen, molecule, O2, are polar.
O True
O False
Answer:
true
Explanation:
How many moles of a gas would occupy 11.4 L at 273K and 2.00 atm?
Answer:
1.02mol
Explanation:
Using the general gas equation below;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K)
According to the information provided in this question,
P = 2.0 atm
V = 11.4L
T = 273K
n = ?
Using PV = nRT
n = PV/RT
n = 2 × 11.4/ 0.0821 × 273
n = 22.8/22.41
n = 1.017
n = 1.02mol
What is the state change of a gas to a liquid is called?
Answer:The process in which a gas changes to a liquid is called condensation. Other examples of condensation are shown in Figure below. A gas condenses when it is cooled below its boiling point.
Explanation:
There are 4 phases for h20 solid liquid vapour and gas.
In the vacuum of space there are only 2 phases solid and gaseous, both liquid and vapour cannot exist in the absolute freezing temperature of the vacuum of space and crystalise instantly.
Watch a space shuttle dump water in space and it instantly freezes, and when in direct sunlight instantly turn to its gaseous phase and becomes invisible to the naked eye by the process of sublimation.
When h20 freezes in the shadow of the shuttle to ice crystals they instantly sublimate to the a gaseous state when they come into contact with direct sunlight.
You can see all 4 phases if you place ice cubes [ solid phase ] in a pan on a stove, the Solid beComes liquid [ liquid phase ]and the liquid becomes a gas in the bottom of the pan when the water boils, [ gaseous phase ] the bubbles coming up from the bottom are the instant phase change from liquid to gas, when the gas bubbles break the surface of the water and the gas comes into contact with the cooler air the gas instantly starts to condense to water droplets i.e. the vapour phase
You can see through the bubbles because h20 in its gaseous phase is invisible to the naked eye.
Gaseous h20 is hot dry and invisible
Vaporous h20 is warm wet and visible
Gaseous h20 is known as a condensing gas in physics because it condenses obviously, condensing gases are also known as optically active gases or radiatively active gases.
Hope this helps all the 3 phase numpties who think vapour i.e. water droplets is actually gas, it isnt or it wouldn’t be called vapour it would be called gas.
Liquid water has to reach its boiling point before it will phase change to its gaseous phase.
Vapor has to boil before the water droplets will phase change to a gaseous state, steam is not gas it is condensing gas i.e. vapour at a lower temperature than boiling point.
hope this helps have a nice day
Which of the following arrangements of electrons represent Potassium? *
a. 2,6,3,8
b. 2,7,8,2
c. 2,8,8,1
d. 2,9,7,1
help pls this is physical science (9th grade )
Answer:
mamamkalalllaamakkaoakmaa
What does the symbol NaCl(aq) mean?
Answer:
The (aq) means that the NaCl is dissolved in water.
Explanation:
Answer:
A water-based solution of sodium chloride
Explanation:
ck12
A mixture of gases in a container has a pressure of 1275.5 mm Hg. If the pressure of CO2 gas is 335.3 mm Hg and the pressure of N2 gas is 418.0 mm Hg, what is the pressure of O2 gas.
When filling a weather balloon with gas you have to consider that the gas will expand greatly as it rises and the pressure decreases. Let's say you put about 10.0 moles of He gas into a balloon that can inflate to hold 5000.0L. Currently, the balloon is not full because of the high pressure on the ground. What is the pressure when the balloon rises to a point where the temperature is -10.0°C and the balloon has completely filled with the gas.
Answer:
0.0432 atm
Explanation:
Step 1: Given data for when the balloon is full
Moles of Helium (n): 10.0 molVolume of the balloon (V): 5000.0 LTemperature (T): -10.0 °CIdeal gas constant (R): 0.0821 atm.L/mol.KStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = -10.0°C + 273.15 = 263.2 K
Step 3: Calculate the pressure of He in the balloon
We will use the ideal gas equation.
P × V = n × R × T
P = n × R × T/V
P = 10.0 mol × (0.0821 atm.L/mol.K) × 263.2 K/5000.0 L = 0.0432 atm
Given : 4.50 molte
How many moles of ammonia would you get if 4.50 moles of hydrogen gas
reacted