Answer:
they reduce viral transmission
They prevent asymptomatic spread
You're protecting others from illness.
They're mandated by law in some states
They're good hygiene in general
If I add 25mL of water to 125 mL of 0.25 M NaOH solution, what will the molarity of the diluted solution be?
Answer:
0.208333 M
Explanation:
M2=M1V1/V2=(0.25 M)(125mL)/(125mL+25 mL)= 0.208333 M
How can I express the composition of a solution?
Answer:
It can be expressed in several ways: molarity (moles of solute per liter of solution); mole fraction, the ratio of the number of moles of solute to the total number of moles of substances present; mass percentage, the ratio of the mass of the solute to the mass of the solution times 100; parts per thousand (ppt), grams ...
Explanation:
It can be expressed in several ways: molarity (moles of solute per liter of solution); mole fraction, the ratio of the number of moles of solute to the total number of moles of substances present; mass percentage, the ratio of the mass of the solute to the mass of the solution times 100; parts per thousand (ppt), grams ...
Calculate the number of moles in 3.01 x 10²² atoms of calcium.
Answer:
Using dimensional analysis:
3.01x1022 molecules CO2 x 1 mol CO2/6.02x1023 molecules x 44. g CO2/mole = 2.20 g CO2
Explanation:
If you use 65.34 g of Al2S3, how many grams of AICl3 can be produced?
Answer:
sorry po
indi ko po maintindihan
A 0.239 gram sample of a gas in a 100-ml flask exerts a pressure of 603 mm Hg at 14 Celsius. What is the gas? (Hint: don’t forget BRINCLHOF)
A) chlorine
B) nitrogen
C) krypton
D) xenon
D) oxygen
Please help me and explain how u got ur answer
Answer:
A) chlorine
Explanation:
To solve this question we can use:
PV = nRT
In order to solve the moles of the gas. With the moles and the mass we can find the molar mass of the gas to have an idea of its identy:
PV = nRT
PV / RT = n
Where P is pressure: 603mmHg * (1atm / 760mmHg) = 0.7934atm
V = 100mL = 0.100L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 14°C + 273.15 = 287.15K
0.7934atm*0.100L / 0.082atmL/molK*287.15K = n
3.37x10⁻³ moles of the gas
In 0.239g. The molar mass is:
0.239g / 3.37x10⁻³ moles = 70.9g/mol
The gas with this molar mass is Chlorine, Cl₂:
A) chlorineThe acidic ingredient in vinegar is acetic acid. The pH of vinegar is around 2.4, and the molar concentration of acetic acid in vinegar is around 0.85 M. Based on this information, determine the value of the acid ionization constant, Ka, for acetic acid.
Answer: The value of acid ionization constant [tex]K_a[/tex] for acetic acid is [tex]1.87\times 10^{-5}[/tex]
Explanation:
[tex]CH_3COOH\rightarrow H^+CH_3COO^-[/tex]
cM 0 0
[tex]c-c\alpha[/tex] [tex]c\alpha[/tex] [tex]c\alpha[/tex]
So dissociation constant will be:
[tex]K_a=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]
Give c= 0.85 M and [tex]pH[/tex] = 2.4
[tex]pH=-log[H^+][/tex]
[tex][H^=}=c\times \alpha=10^{-2.4}=3.98\times 10^{-3}[/tex]
[tex]K_a=?[/tex]
Putting in the values we get:
[tex]K_a=\frac{(3.98\times 10^{-3})^2}{(0.85-3.98\times 10^{-3})}=1.87\times 10^{-5}[/tex]
Thus the value of acid ionization constant [tex]K_a[/tex] for acetic acid is [tex]1.87\times 10^{-5}[/tex]
Why should we try to use less oil, natural gas and electricity?
One major problem with wind and solar energy is that they are conditional. Explain how hydroelectric pumped storage could be used to eliminate this
obstacle? *
Link to the article https://thinkprogress.org/the-inside story-of-the-worlds-biggest-battery-and-the-future-of-renewable-energy-8984c81283c/
Answer:
Hydroelectric pumped storage can be used to eliminate the conditional nature of wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.
Explanation:
Pumped-storage hydroelectricity is a type of hydroelectric energy storage used by electric power systems to store excess electrical power during periods of low demand for later release at periods when demand for energy rises again. It stores energy in the form of gravitational potential energy of water, pumped from a lower level reservoir to a higher level reservoir.
At times of low electrical demand, excess generated energy is used to pump water into the upper reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine, generating electricity.
This form of energy storage is useful in circumventing the conditional nature of renewable energy sources such as wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.
(c) Write the balanced neutralization reaction and calculate the volume in mL of a 1.420 M NaOH solution required to titrate 25.00 mL of a 5.400 M H2SO4 solution
Answer:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
190.14 mL of the NaOH solution would be required.
Explanation:
The balanced reaction is:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂ONow we calculate how many H₂SO₄ moles are there in 25.00 mL of a 5.400 M solution, using the definition of molarity:
Molarity = moles / litersMoles = Molarity * liters25.00 mL * 5.400 M = 135 mmol H₂SO₄Now we convert H₂SO₄ moles into NaOH moles, using the stoichiometric coefficients of the balanced reaction:
135 mmol H₂SO₄ * [tex]\frac{2mmolNaOH}{1mmolH_2SO_4}[/tex] = 270 mmol NaOHFinally we calculate the volume of a 1.420 M solution that would contain 270 mmoles:
Molarity = moles / litersliters = moles / molarity270 mmol / 1.420 M = 190.14 mLBRAINLIESTTTT
If a solution has pOH of 5.2 the pH of the solution is?
A. 0.17
B. 5.2
C. 6x10-6
D. 8.8
Answer:
D 8.8
Explanation:
To solve this question you must know that, using the kw equation:
Kw = 1x10⁻¹⁴ = [H⁺] [OH⁻]
-log 1x10⁻¹⁴ = -log ([H⁺] [OH⁻])
14= -log [H⁺] + -log [OH⁻]
As pH = -log[H⁺] and pOH = -log [OH⁻]
we can obtain the equation:
pH = 14 - pOH
As the pOH of the solution is 5.2:
pH = 14 - 5.2
pH = 8.8
Right option is:
D 8.8do you really get 7 years of bad luck if you crack a mirror :(
Answer:
nope its a myth don't worry :)
Calculate the mass of 488 moles of calcium carbonate, CaCO3
Help please!
Answer:
≅ 4.88 grams (3 sig. figs.)
Explanation:
to convert from ...
grams to moles => divide by formula wt.
moles to grams => multiply by formula wt.
this problem:
mass in grams = 488moles / 100.09g/mol = 4.875612 grams (calculator)
≅ 4.88 grams (3 sig. figs.)
2NaCl ---> 2Na + Cl2
What are the atoms of the products
Answer: ...
Explanation:
Sodium, chlorine
Answer:
2Na = 2 Sodium [has 2 atoms]
Cl2 = Dichlorine (Chlorine) [has 2 atoms]
Is this what you wanted?? I'm not entirely sure if this is the answer you were looking for.
How many carbon atoms are in 1.25 mol of silver acetate?
The number of carbon atoms present in 1.25 mol of silver acetate is 1.875 × 10²³.
What is Avogadro's number?Avogadro's number is define as the number of atoms of any substance present in one mole of that substance, and it is equal to 6.022 × 10²³, i.e.
1 mole = 6.022 × 10²³ atoms/mol
Given moles of silver acetate = 1.25 moles
Number of atoms of silver acetate in 1.25 moles = 1.25 × 6.022 × 10²³ = 7.5×10²³
Molecular formula of silver acetate is CH₃CO₂Ag, means in this molecule total 8 atoms are present so number of carbon atom will be calculated as:
Carbon atoms = (2× 7.5 × 10²³) / 8 = 1.875 × 10²³ atoms [here we multiply by 2 because 2 atoms of carbon is present in olecule]
Hence required atoms of carbon is 1.875 × 10²³.
To know more about Avogadro's number, visit the below link:
https://brainly.com/question/1513182
help me how to do this
Answer:
sry i don't know that language
What type of chemical replacement is RbNO3 + BeF2 →Be(NO3)2 + RbF
Answer:
Double replacement
Explanation:
In H20 does the 2 apply to
Hydrogen, Oxygen, or Both?
Answer:
The difference is due to the fact that one water molecule has two hydrogen atoms to one oxygen atom, as explained above. This means it takes two water molecules (2 H2O) to make one oxygen molecule (O2)
Explanation:
Answer:
In H20 does the 2 apply to Hydrogen
Explanation:
In H₂O there is two atoms of hydrogen and 1 atom of Oxygen
Hence, In H20 does the 2 apply to Hydrogen
-TheUnknownScientist
If you want to make 174 grams of NiFz, how many moles of HF will you need, using
the following balanced chemical equation? Ni + 2 HF - NiF2 + H2
Answer:
3.6mol
Explanation:
The balanced chemical equation of this reaction is given as follows:
Ni + 2HF → NiF2 + H2
Based on the above equation, 2 moles of HF will react to produce 1 mole of NiF2.
According to this question, to make 174 grams of NiF2, we find the number of moles of HF required. However, we first convert the mass value of NiF2 to mole value using;
mole = mass/molar mass
Molar mass of NiF2 = 58.7 + 19(2)
= 58.7 + 38
= 96.7g/mol
mole = 174/96.7
mole = 1.799mol of NiF2
Hence, if 2 moles of HF will react to produce 1 mole of NiF2.
- 1.799mol of NiF2 will require (1.799 × 2) = 3.598
= 3.6mol of HF.
How many grams is 2.40 x 1023 molecules of N,O,? (5 pts)
PLS HELP ASAP
Answer:
30.26 grams of N₂O₃
Explanation:
Divide by Avogadro's number. This leaves you with the number of moles. Then, multiply by the molar mass of N₂O₃
Calculate the amount of heat energy required to heat up 15.9 grams of ice from -4 °C to 14°C.
Answer:
581 Joules.
Explanation:
Using the formula;
Q = m × c × ∆T
Where;
Q = amount of heat absorbed (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the information provided in this question;
Q = ?
mass of ice = 15.9g
initial temperature = -4°C
final temperature = 14°C
Hence, ∆T = 14 - (-4) = 14 + 4 = 18°C
specific heat capacity (c) of ice in J/g°C = 2.03 J/g°C
Using Q = m × c × ∆T
Q = 15.9 × 2.03 × 18
Q = 32 × 18
Q = 581 Joules.
8. Of what importance is a smoker to a person keeping bees?
Answer:
they help to calm the bees when the person keeping the bees inspects there hives.
Which of the following relationships can be measured in light years?
the length of time it takes light to reflect from a plane mirror
the amount of light absorbed by the Earth
the index of refraction of a mirage
the distance between stars and galaxies
All of the choices are correct.
Which element, when combined with phosphorus, would form an ionic compound?
A) Carbon.
B)Oxygen.
C)Magnesium.
D)Boron.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the correct option is option C.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.
Since phosphorus is a nonmetal, we need a metal. Out of given option the only element that is metal is Magnesium while others are non metal.
Therefore, the correct option is option C.
To learn more about chemical compound, here:
https://brainly.com/question/26487468
#SPJ2
how many grams of AgNO3 (MM=169.87) are needed to prepare 0.125 M solution in 250 mL of water?
a. 0.5 g
b. .03 g
c. 5.3 g
d. 84.9g
Answer:
Correct answer-C 5.3g
Explanation:
Molarity = no. of moles of solute/ volume of of solution in litre
olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125
olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125one mole AgNO3 weighs 169.87 gm,
olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125one mole AgNO3 weighs 169.87 gm,so the mass of 0.03125 moles of AgNO3 = 0.03125×169.87= 5.3084g
The grams of AgNO₃ are needed to prepare 0.125 M solution in 250 mL of water is 5.3 grams.
How do we calculate mass from moles?Moles is a unit which is used to define any amount and it is calculated as:
n = W/M, where
W = required mass
M = molar mass
Given molarity of AgNO₃ = 0.125 M
Volume of water = 250mL = 0.25L
moles (n) from the molarity (M) will be calculated as:
n = M × V
n = (0.125)(0.25) = 0.0312 moles
Now we calculate the mass of AgNO₃ by using the above formula as:
W = (0.0312mol)(169.87g/mol)
W = 5.30 g
Hence option (c) is correct.
To know more about moles, visit the below link:
https://brainly.com/question/15374113
plz help me 14 points
A student transfers a gas at STP from a 11.0 L tank to a 25.0 L tank. If the pressure
remains constant, what is the new temperature?
. Consider a sample of oxygen gas at 27° C with a volume of 9.55L at a pressure
Answer:620 k
Explanation:
Where do we get our energy from ?
Answer:
energy
Explanation:
4 Weathering Assessment
2 of 132 of 13 Items
Question
POSSIBLE POINTS: 5.88
On a hot summer day, you and your friend decide to make a drink by mixing ice cubes, water, sugar, and Kool-Aid mix. Which of the following statements best describes what type of change has occurred?
This is an example of chemical change because the sugar dissolved.
This is an example of chemical change because the sugar dissolved.
This is an example of a physical change because the sugar dissolved
This is an example of a physical change because the sugar dissolved
This is an example of a physical change because the ice cubes began to melt.
This is an example of a physical change because the ice cubes began to melt.
This is an example of a chemical change because the Kool-aid dissolved and turned the water red.
Answer:
This is an example of chemical change because the Kool aid dissolved and turned the water red
How many molecules of As4010 are in 6.2 mol of As4010?
Match the word to the definition
Question 1 options:
simple diffusion
osmosis
facilitated diffusion
1.
Molecules move from high to low concentration
2.
Molecules move from high to low concentration with a transport protein
3.
Diffusion of water through a selectively permeable membrane