Answer:
the first one
Explanation:
I looked it up:P
Only the 2nd answer is right, uncheck the 1st one
Explanation:
If we had a chemical formula like [tex]3(O_{2} )[/tex] the 3 means there are 3 molecules of [tex]O_{2}[/tex]. The 2 means there are two atoms of oxygen in each molecule.
1L = 1000 mL
Molarity (M) = moles of solute / L of solution
Calculate the moles of NaCl required to prepare 250 mL of 1.5 M aqueous solution.
Answer:· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
Explanation:
calculate the ph of one solution containing 0.1 M formic acid and 0.1 M sodium formate before and after the addition of 1mL of 5 M Naoh. how much could the Ph change if the NaOh were added to 1 L of pure water
Answer:
Pka of formic acid (HCOOH)= 3.75
pH= PKa +log [ Sodium formate/ formic acid] = 3.75
NaOH reacts with HCOOH as HCOOH (aq) + NaOH(aq) --> NaCHO2 (aq) and H2O (l)
Moles of HCOOH= 0.1*1= 0.1 moles
Moles of NaOH= 5*1/1000= 0.005 moles
HCOOH is in excess and the excess is = 0.1 - 0.005 = 0.095
Moles of sodium formate = 0.005 + 0.1 = 0.105 moles of HCOOH= 0.095
volume after mixing = 1 + 5 /1 000=1.005
Concentrations : HCOOH= 0.095/1.005 sodium formate= 0.105/1.005
pH= 3.75+log (0.105/0.095)=3.85
When NaOH is added, molarity is , 1*5= 1000*M
M= 5/1000=0.005
The pH remains the same. Only the molarity of NaOH changes.
5. What types of surfaces would result in greater friction?
Answer:
Rough and irregular surface
these surfaces tends a lot of friction
but on smooth surface there is least friction
hope it helps
How can you determine if elements have the same properties?
Answer:
You will know if elements have the same properties if they are in the same column (up and down) on the periodic table.
Explanation:
Ex: Lithium and a hydrogren has the same properites bcause they are both on the same line/column. Columns are up and down the table and rows are left and right. Hope this helps
A change resulting in one or more new substances being formed is a?
A. nuclear reaction
B.physical property
C. chemical change
D.physical change
Answer:
C. Chemical change
Explanation:
A physical change is where something is changed but it doesnt affect the build up of the chemical. For example, if you broke sticks and threw them on the ground, that would be a physical change because the change is happening to the physical being of the object and not its chemical buildup. However, if you lit those sticks on fire, that would be considered a chemical change because you end up with two substances, ash and the remnants of the stick. A nuclear reaction would result in something blowing up so its not that. And a physical property is like what it looks like or how it smells. Hope I helped you!
what makes up the cell menbrane
With few exceptions, cellular membranes — including plasma membranes and internal membranes — are made of glycerophospholipids, molecules composed of glycerol, a phosphate group, and two fatty acid chains. Glycerol is a three-carbon molecule that functions as the backbone of these membrane lipids.
Explanation:
the principal components of plasma membrane are lipids phospholipid and cholesterol proteins and carbohydrates
how proved that carbon is present in sugar?
In all living organisms, in substances like carbohydrate, starch, urea etc. To prove sugar contains carbon, take a little amount of sugar in spoon and heat it gently till it melts and turned into yellowish color. On further heating it changes into brown colored mass and then black, which is charcoal.
Answer: sugar treated with strong sulphur acid turns to black
Explanation: sulphur acid removes water from sugars and carbon is left in residue.
This should not to try at home. Water boils when high temperature is achieved.
Also smell of burned sugar occurs
Heat transfer that occurs within or between solid objects is called
Answer:
conduction
Explanation:
The answer is Conduction
If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of He occupy under the same conditions?
Answer:
the volume occupied by 3.0 g of the gas is 16.8 L.
Explanation:
Given;
initial reacting mass of the helium gas, m₁ = 4.0 g
volume occupied by the helium gas, V = 22.4 L
pressure of the gas, P = 1 .0 atm
temperature of the gas, T = 0⁰C = 273 K
atomic mass of helium gas, M = 4.0 g/mol
initial number of moles of the gas is calculated as follows;
[tex]n_1 = \frac{m_1}{M} \\\\n_1 = \frac{4}{4} = 1[/tex]
The number of moles of the gas when the reacting mass is 3.0 g;
m₂ = 3.0 g
[tex]n_2 = \frac{m_2}{M} \\\\n_2 = \frac{3}{4} \\\\n_2 = 0.75 \ mol[/tex]
The volume of the gas at 0.75 mol is determined using ideal gas law;
PV = nRT
[tex]PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\since, \ \frac{RT}{P} \ is \ constant,\ then;\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1n_2}{n_1} \\\\V_2 = \frac{22.4 \times 0.75}{1} \\\\V_2 = 16.8 \ L[/tex]
Therefore, the volume occupied by 3.0 g of the gas is 16.8 L.
The volume occupied by 3.0 g of He is mathematically given as
V2=16.8L
What volume does the 3.0 g of He occupy?Question Parameters:
If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of H
Generally, the equation for the gas equation is mathematically given as
PV=nRT
When the reacting mass is 3g
n2=3/4
n2=0.75
Therefore
V1/n1=V2/n2
Where
n1=1
[tex]V2=\frac{22.4*0.75}{1}[/tex]
V2=16.8L
Read more about volume
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Identify the type of reaction.
Al + MgSO4 = Al2(SO4)3 + Mg
Answer: its combustion
Explanation:
Solution remained colorless.
During the experimentation, the test tube was gently heated in a Bunsen burner flame for 60 seconds. What was the reason for this specific
procedure?
A)
Heating was done to initiate the combustion of the metal in water.
B)
Heating was done to confirm that no chemical reaction would take
place in acid
0
Heating was done to precipitate the chemical change in each test
tube containing water
D)
Heating helped released the hydrogen contained in water
molecules so students would have a positive H+ test.
According to the text, fission occurs when the nucleus
two lighter nuclei.
Answer:
Splits into
Explanation:
Because fission reaction is divided into two or more pieces.
7x[(7+7)divide7]
PLEASE HELP
Answer:
ik this isnt the answer but mathwa will solve all yours problems
Explanation:
A sample of carbon dioxide gas at a pressure of 686 mm Hg and a temperature of 73 C, occupies a volume of 6.34 liters. If the gas is cooled at constant pressure to a temperature of 35 C, the volume of the gas sample will be ____________ L.
Recall the ideal gas law,
P V = n R T
Find the amount of CO₂ in the sample, n :
P = 686 mm Hg ≈ 91,459 Pa
V = 6.34 L
R = 8.3145 J/(mol•°K)
T = 73 °C = 346.2 °K
→ n = P V / (R T ) ≈ 0.20147 mol
Now find the volume V of the sample when the temperature T is 35 °C = 308.2 °K :
V = n R T / P ≈ 5.6349 L ≈ 5.63 L
The diagrams below show the alignment of the Sun, the Moon, and Earth.
Answer:A
Explanation: I learned it from a gizmo
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Explanation:
There will be a transfer of thermal energy (heat) from the hot metal plate to the surrounding air. This transfer of energy equates to a transfer of kinetic energy in the molecules. As the plate loses heat, the molecules in the plate will lose kinetic energy and slow down. As the surrounding air gains heat, the molecules will gain kinetic energy and speed up.
Answer: C
Explanation:
How many calcium atoms are in 56.5 g of calcium?
Answer:
there are 8.501×10^23 atoms of Ca atoms
Which if the following numbers in your personal life are exact numbers?
A. Your cell phone number
B. Your weight
C. Your IQ
D. Your driver's license number
E. The distance you walked yesterday
Answer:
I think D
Explanation:
Your cell phone number and your driver's license number are the numbers of your personal life that are exact.
In this context, an exact number refers to a number that if it undergoes any modification will not refer to the same thing that it referred to before that modification.
For example, my phone number is 12345. This number is exact because it cannot be changed because or else it would cease to be my phone number, that is, if someone wants to call me and writes the number 12346 it is no longer my number.
Addicionally, if my driver's license number is 112233 it is an exact number because if it is modified it would be the number of another driver.
According to the above, options B, C, and E are incorrect because they are inaccurate numbers because if they are modified they all refer to me and they would not change their meaning.
Learn more in: https://brainly.com/question/17093923
What are the two products of an acid base neutralization reaction?
Answer:
Neutralization reactions occur when two reactants, an acid and a base, combine to form the products salt and water.
Explanation:
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Answer: Water and NaCl is always formed
Explanation:
I hope this helped!
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What is the mass percent of potassium sulfate in solution if 78g of potassium sulfate is dissolved in 500 mL of water? (The density of water is 1.00 g/mL)
Answer:
13.5 %
Explanation:
First we calculate the mass of 500 mL of water, using its density:
Volume * Density = Mass500 mL * 1.00 g/mL = 500 gThen we calculate the mass percent of potassium sulfate, using the formula:
Mass of Potassium Sulfate / Total Mass * 100%
78 g / (78 + 500) g * 100 % = 13.5 %The molecular weight for the compound from the previous question is
64.07 g/mol. What is its molecular formula?
Fission and fusion are alike in many ways. However, one difference is
A)
Fusion forms dangerous nuclear waste that is difficult to dispose whereas
fission does not.
Eliminate
B)
Fission is a controllable chain reaction and fusion is not.
Fusion results in a greater product mass whereas fission does not.
D)
Raw materials for fission are cheaper and easy to get.
Explanation:
Fusion vs Fission
In fission, energy is gained by splitting apart heavy atoms, for example uranium, into smaller atoms such as iodine, caesium, strontium, xenon and barium, to name just a few. However, fusion is combining light atoms, for example two hydrogen isotopes, deuterium and tritium, to form the heavier helium. Both reactions release energy which, in a power plant, would be used to boil water to drive a steam generator, thus producing electricity.
Answer:
B
Explanation:
i did this
is oxygen a beginning substance or ending substance?
Why does an asteroid get hotter when it goes close to the sun?
What is a hot spot? Must be in your own words ( please hurry)
Answer:
It depends. what hot spot are you looking for?
Answer:
A hot spot is an area on Earth over a mantle plume or an area under the rocky outer layer of Earth, called the crust, where magma is hotter than surrounding magma. The magma plume causes melting and thinning of the rocky crust and widespread volcanic activity.
Explanation:
Hope this is what you mean be hot spot!
I hope this helps you!
This equation shows the combustion of methanol.
2CH2OH(1) +302(g) → 2C02(g) + 4H2O(g)
How many liters of carbon dioxide gas at STP are produced by the combustion of 64.0 g of methanol
(CH3OH)
A. 44.8L
B. 89.6 L
C. 11.2L. D. 22.4L
Answer: 44.8 L
Explination:
44.8 liters of carbon dioxide gas at STP are produced by the combustion of 64.0 g of methanol. Therefore, option A is correct.
What is combustion ?Combustion is a chemical reaction between two or more substances, usually involving oxygen, that produces heat and light in the form of a flame.
Combustion is a high-temperature exothermic redox chemical reaction that occurs between a fuel and an oxidant, frequently atmospheric oxygen, to produce oxidized, often gaseous products in a mixture known as smoke.
The flash point of methanol is extremely low. This means that even trace amounts of ignition material can start a fire. 44.8 liters of carbon dioxide gas at STP are produced by the combustion of 64.0 g of methanol.
Thus, option A is correct.
To learn more about the combustion, follow the link;
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explain what you would do expect caesium astatide to look like .will it be soluble in water ?explain your reasoning
Answer:
it will not be soluble in water Becoz it can only be
separated by passing it through silver nitrate solution
Explanation:
i hope you understand
pleaaaaase helppppppppppppp ASAP
Answer:
Explanation:
a) The forward reaction is exothermic, hence when temperature is increased the equilibrium shift towards the reactants side to get rid of the excess energy. This will mean that more reactants are produced decreasing yield
b) There are a fewer number of moles of gas on the right side compared to the left side (Just count the coefficients before each compound) so a higher pressure will mean that the equilibrium will shift towards the products side in order to decrease the pressure. This will mean that more products are formed increasing yield
c) When something is powdered it's surface area to volume ratio increases. A higher surface area means that the particles around it have more area to work on so the frequency of collisions will increase increasing the rate of reaction. This is why iron is powdered.
In this field of sunflowers variation exists some flowers are tall others short
Answer:
Some flowers are tall, others short, and finally some plants are an intermediate height. The tallest plants shade the shorter; the taller plants are
Explanation:
A chunk of zinc is added to a solution of gold (III) nitrate to extract the gold. The reaction forms,
zinc nitrate and the precipitate gold.
Explanation:
Gold (AU)................