Freddie is carrying out an experiment for which he has to maintain a water bath at a temperature of 37°C. He has a choice of four thermometers, all of which read from 0 to 100°C.Thermometer A is marked in 5°C intervals, B in 1°C intervals, C in 10°C intervals and D in 20°C intervals. Which thermometer should Freddie choose to monitor the water bath's temperature?
B
D
A
C
Answer:
C
Explanation:
because 37 does not end with 5 or 0, so it'd be harder to see if the water temperature is accurate if your thermometer goes up by 5s or 10s. And using D, the one that goes up by 20s is out of the question, it'd be too difficult to read. Using a thermometer that goes up by 1s is just best because you can be positive when the water is at 37°C
What is the molarity of a solution consisting of 105 grams of calcium nitrate and 280. grams of water?
Answer:
About 2.29 M.
Explanation:
Recall that molarity is defined by moles of solute over liters of solution.
Our solute is 105 grams of calcium nitrate (Ca(NO₃)₂)).
Convert 105 grams of Ca(NO₃)₂ to moles. The molecular weight of Ca(NO₃)₂ is 164.10 g/mol:
[tex]\displaystyle 105\text{ g Ca(NO$_3$)$_2$}\cdot \frac{1\text{ mol Ca(NO$_3$)$_2$}}{164.10\text{ g Ca(NO$_3$)$_2$}} = 0.640\text{ mol Ca(NO$_3$)$_2$}}[/tex]
Convert 280. grams of water to liters. Recall that the density of water is given by 1.00 g/mL:
[tex]\displaystyle \begin{aligned} D & = \frac{m}{V} \\ \\ V & = \frac{m}{D} \\ \\ & = \frac{(280.\text{ g})}{\left(\dfrac{1.00\text{ g}}{1\text{ mL}}\right)} \\ \\ & = 280. \text{ mL}\cdot \frac{1\text{ L}}{1000\text{ mL}} = 0.280\text{ L soln.}\end{aligned}[/tex]
Hence, the molarity of the solution is:
[tex]\displaystyle \begin{aligned} \text{M} &= \frac{\text{ mols solute}}{\text{L soln.}} \\ \\ & = \frac{(0.640\text{ mol})}{(0.280\text{ L soln.})} \\ \\ & = 2.29\text{ M} \end{aligned}[/tex]
In conclusion, the solution is about 2.29 M.
58.0 g of K2SO4 was dissolved in 500 g of water.
What is the molality of the solution? (Molar mass of
K2SO4 = 174.0 g/mol)
m
Round your answer to the nearest hundredth. Do not include units
in your answer.
Answer:
0.67
Explanation:
Molality is mols of solute over kilograms of solvent
there are 58/174 mols of solute, and 0.5 kg of solvent
(58/174)/0.5=0.6666...
Round to the nearest hundreth to get 0.67
free brainiest to whoever writes me the best love note! :) <3 dont miss the opportunity!!!
Answer:
Hi! I hope you're having a wonderful day, if not, I hope it gets better, much love and kindness! Be great!
How many liter are in 55.5 grams of neon?
which molecule can't be exist?
A)NCl3 B)OF6 C)ONF3 D)PCl3
Answer:
OF6
Explanation:
Oxygen and fluorine have almost the same electronegativity, so oxygen isn't able to donate enough electron density to fluorine to form OF6. Atomic size. There isn't enough room around an oxygen atom for six fluorine atoms.
:-befrank
If you want to produce 18.48 grams of NaCl what is the minimum amount of each reactant that you must start with
The minimum amount of NaOH and HCl that must be present to produce 18.48grams of NaCl is 12.6g and 11.5g respectively.
Calculation of amount of reactantsThe balanced neutralization reaction equation for the formation of NaCl is,
NaOH + HCl ---> NaCl + H2
The molar mass of NaOH = 23+16+1 = 40g/mol
The molar mass of NaCl = 23 +35.5 = 58.5g/mol
If 40g of NaOH = 58.5g of NaCl
∴ x g of NaOH = 18.48g of NaCl
Make xg the subject of formula,
x g of NaOH = 40 × 18.48/58.5
= 739.2/58.5
= 12.6g of NaOH
The molar mass of HCl = 1 +35.5 = 36.5g/mol
If 36.5g of HCl= 58.5g of NaCl
∴ x g of HCl = 18.48g of NaCl
Make xg the subject of formula,
x g of HCl = 36.5 × 18.48/58.5
= 674.52/58.5
= 11.5g of HCl
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HELP PLS (IT IS NOT THE THIRD ONE)
Answer:
A. would be your answer
Explanation:
Decomposers are especially important in retaining nutrients in their cells thus preventing loss of those nutrients from the root zone.
In an ecosystem, the decomposing web is important because decomposers help remove waste and use that energy to provide food for other animals.
What is an ecosystem?An ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the ecosystem through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass which is present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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Water’s molar mass is 18.01 g/mol. the molar mass of glycerol is 92.09 g/mol. at 25°c, glycerol is more viscous than water. which substance has the stronger intermolecular attraction? glycerol because it has a larger molar mass glycerol because it is more viscous and has a larger molar mass water because it has a lower molar mass water because it is less viscous and has a lower molar mass
Glycerol has the stronger intermolecular attraction because it is more viscous and has a larger molar mass.
What is Viscosity?This is the ability of substances to resist flow and is common among fluids such as air and liquid.
Glycerol however has a stronger intermolecular attraction because it is more viscous and has a larger molar mass because they have a direct relationship.
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Answer:
A-glycerol because it has a larger molar mass
Explanation:
Edge 2022 :)
Since helium is lighter than air, it is difficult to measure the mass of a sample, so to find out the mass of helium in a birthday balloon, a student transferred the helium to a fixed 1. 50 l vessel at 25. 0 °c and found the pressure to be 3. 04 atm. What mass of helium is in the balloon in grams?.
A 1.50-L vessel is filled with helium at 25.0 °C and 3.04 atm. Under these conditions, the mass of helium is 0.744 g.
What is an ideal gas?An ideal gas is that whose particles have negligible volume and intermolecular forces.
A 1.50 L vessel at 25.0 °C contains He at a pressure of 3.04 atm.
Step 1. Convert 25.0 °C to Kelvin.We will use the following expression.
K = °C + 273.15 = 25.0 + 273.15 = 298.2 K
Step 2. Calculate the moles of He.We will use the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 3.04 atm × 1.50 L / (0.0821 atm.L/mol.K) × 298.2 K = 0.186 mol
Step 3. Calculate the mass of He.The molar mass of He is 4.00 g/mol.
0.186 mol × 4.00 g/mol = 0.744 g
A 1.50-L vessel is filled with helium at 25.0 °C and 3.04 atm. Under these conditions, the mass of helium is 0.744 g.
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In the Lewis symbol for a fluorine atom, there are __________ paired and __________ unpaired electrons.
In the Lewis symbol for a fluorine atom, there are 4 paired and 1 unpaired electrons.
However, paired electrons simply means are 2 electrons occupying the same orbital in an atom or molecule of a substance
On the other end, unpaired electron is a single electron that occupies an orbital of an atom.
What is an atom?An atom is the smallest part of an element which can take part in a chemical reaction.
Some atoms of elements are:
MonoatomicDiatomicTriatomicPolyatomicIn conclusion, in the Lewis symbol for a fluorine atom, there are 4 paired and 1 unpaired electrons.
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Answer: 6, 1
Explanation:
The balanced equation for the aerobic reaction is:
Zn + 2 HCl → ZnCl2 + H2
How much hydrogen gas is produced from 5 g of HCl?
Answer:
1.85 g of hydrogen gas will form!
Explanation:
1. Write the balanced equation.
Zn
+
2HCl
→
ZnCl
2
+
H
2
2. Calculate the moles of
Zn
.
Moles of Zn
=
30.0
g Zn
×
1 mol Zn
65.38
g Zn
=
0.4589 mol Zn
3. Calculate the moles of
H
2
.
Moles of H
2
=
0.4589
mol Zn
×
2 mol H
2
1
mol Zn
=
0.9177 mol H
2
4. Calculate the mass of
H
2
.
Mass of H
2
=
0.9177
mol H
2
×
2.016 g H
2
1
mol H
2
=
1.85 g H
2
Time (sec) [CH4] (mol/L)
0 1.2
20 1.0
40 0.9
60 .85
CH4 (g) + O2 (g) -----> CO2 (g) + H2O (l)
Given the above table and equation above, calculate the average rate of consumption of oxygen from time 20 seconds to time 60 seconds.
Based on the table and the equation of reaction; the
rate of consumption of oxygen between time 20 and 40s is 0.005 M/srate of consumption of oxygen between time 40 and 60s is 0.0025 M/sWhat is rate of a reaction?The rate of a reaction is the rate at which reactants molecules are consumed or products are formed.
Rate of reaction = change in concentration of reactants or products/ time takenBased on the equation of reaction, the rate of consumption of oxygen is equal to the rate of consumption of methane.
Thus. rate of consumption of oxygen from time 20 seconds to time 60 seconds is calculated as follows:
Rate between 20 and 40 = 1.0 - 0.9/20
Rate of consumption of oxygen = 0.005 M/sRate between 40 and 60 = 0.9 - 0.85/20
Rate of consumption of oxygen = 0.0025 M/sTherefore, the rate of consumption of oxygen decreases with time.
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Explain why you usually can’t use just a single spectral line to confirm the identity of an element.
You can't usually just use a single spectrum line to confirm the identity of an element because there are cases that the emission line id not clearly defined. When the emission line is very weak compared to surrounding noise, in which case the more datapoints you have to build up confidence for the existence of a particular emission spectra, the better.
Select all that apply.
Which items are properties of acids?
soapy
sour
sweet
sharp
possible burns
for 10 points
Answer:
Sour and Possible Burns
Explanation:
Bases are soapy, not acids.
All acids are sour to taste.
Neither bases nor acids are sweet.
Sharp is a physical trait for things such as knives, not acidic liquids.
Acids can cause burns if handled incorrectly.
how many moles of o2 would be required to produce 4 mol h2o?
Hii there !
The reaction accompanying production of water in this case would be -
[tex]\green{ \underline { \boxed{ \sf{2H_2+O_2\longrightarrow 2H_2O}}}} [/tex]
Thus ,by observing the reaction, we can conclude that 2 mole of Hydrogen [tex](H_2 )[/tex]react with 1 mole of oxygen[tex](O_2)[/tex]to produce 2 mole of water [tex](H_2O)[/tex]
Now,
To produce 1 moles of water.
Moles of Oxygen[tex](O_2)[/tex] required [tex] = \frac{1}{2}[/tex] moles
Similarly,
To produce 4 moles of water.
[tex]\implies[/tex] Moles of Oxygen[tex](O_2)[/tex] required = [tex]\frac{1}{2}\times 4[/tex] moles
[tex]\implies[/tex] 2 moles
Hope it helps.
What effect does sunlight have on CO2 molecules?
Answer:
CO2 molecules don't really interact with sunlight's wavelengths. Only after the Earth absorbs sunlight and reemits the energy as infrared waves can the CO2 and other greenhouse gases absorb the energy.
Explanation:
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Carbon dioxide molecules don't directly react with the sunlight but they can absorb the energy in the form of infrared waves when it is emitted after reflection through the Earth's surface.
What are infrared waves?Infrared radiation (IR), sometimes referred to simply as infrared, is a region of the electromagnetic radiation spectrum where wavelengths range from about 700 nanometers (nm) to 1 millimeter (mm).
[tex]CO_2[/tex] molecules don't really interact with sunlight's wavelengths. Only after the Earth absorbs sunlight and reemits the energy as infrared waves can the [tex]CO_2[/tex] and some other greenhouse gases absorb the energy.
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What does net force depend on
Answer:
net force depends upon the object and also the mass of that object
Answer:The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object.
Explanation:
What is a DNA fingerprint and why is it considered individual evidence?
Answer:
DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation.
A DNA sample taken from a crime scene is compared with a DNA sample from a suspect. If the two DNA profiles are a match, then the evidence came from that suspect.
What can you infer about magnetic domains from the fact that they are arrangements of atoms?.
Explanation:
Q. What can you infer about magnetic domains from the fact that they are arrangements of atoms? The individual domains are extremely small.
In ferromagnetic materials, smaller groups of atoms band together into areas called domains, in which all the electrons have the same magnetic orientation. That's why you can magnetize them.An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. The poles of an electromagnet can even be reversed by reversing the flow of electricity.HELPPPPP
A sample of gas contains 6 mol in a 22 L flask at 238 K. What is the pressure of the gas in atmospheres?
The pressure of the sample of gas with the given mol, volume and temperature is 5.33atm.
Ideal Gas LawThe Ideal gas law or general gas equation emphasizes on the state or behavior of a hypothetical ideal gas. It states that "pressure P times volume V is equal to moles times temperature and the universal gas constant. It is expressed;
PV = nRT
Where P is pressure, V is volume, n is the amount of substance, T is temperature and R is the ideal gas constant ( 0.08206 Latm/molK ).
Given the data in the question;
Amount of gas n = 6molVolume V = 22LTemperature T = 238KPressure P = ?We substitute our values into the expression above to determine the pressure of the gas in atmospheres.
PV = nRT
P = nRT / V
P = ( 6mol × 0.08206Latm/molK × 238K ) / 22L
P = 117.18168Latm / 22L
P = 5.33atm
Therefore, the pressure of the sample of gas with the given mol, volume and temperature is 5.33atm.
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Type of force when you open the door. *
1 point
A. applied force
B. friction
C. gravity
D. magnetism
A. applied force
force applied to an object
Answer:
A. Applied force
Explanation:
A. should be the answer because you applied force onto an object to make it move or do what you’d like.
I hope it helps! Have a great day!
Muffin~
just pick the right option
Answer:
A
Explanation:
As CO₂ (carbon dioxide) depends on the air temperature, it is the dependent variableTherefore, air temperature is the independent variableThis is about the relation between carbon dioxide and air temperature, so the soil surface is not a variable to be consideredDuring winter in cold climates, salt is often used on roads to prevent the buildup of slippery ice. Although salt may make driving safer, it can cause the metallic parts of cars to corrode or rust relatively quickly. In a few sentences, please explain what is occurring.
Answer:
this is because the salt may be acidic and also may have oxygen substituent which can lead to rust
During cold winters, the salt present on the roads reacts with the iron and the dew water and results in the formation of the iron oxide as rust.
What is rust?The rust has been given as the iron oxide compound, that has been formed with the reaction of the water with the iron in the presence of oxygen.
In the winters, there has been the presence of the water in the salt, and the interaction of the salt with the iron to form the iron oxide that is rust.
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When the maturities of a bond issue are spread over several dates, the bonds are called.
ANSWER FAST PLS ILL GIVE BRAINLY 5. What are animals called that make their homes underground?
grazers
reptiles
burrowers
meat-eaters
Answer:
burrowers
Explanation:
1. Describe what the following terms mean
Temperature -
Heat -
Exothermic -
Endothermic -
A sealed flask contains 3.82 x 1024 molecules of CO, How many moles of Co, are in the flask?
Answer:
if you meant 3.82* 10^24, the answer is 6.34551495 moles
if you meant 3.28*1024, the answer is 6.49780731*10^-21 moles
since you're going from molecules to moles, you need to divide by Avogadro's number which is 6.02*10^23
what is density/ how does density work
help help
Answer:
Density is the measurement of how tightly a material is packed together. It is defined as the mass per unit volume. Density Formula: ρ = m/V, where ρ is the density, m is the mass of the object and V is the volume of the object.
Explanation:
Answer:
The mass per unit volume of a substance is called density of that substance.
Explanation:
So, How does it works ?
For example: Density of gold is 19300kg/cubic meter. It means that if there gold having volume of a cubic meter its mass will be 19300 kg... Density of plastics are less than that of density of metals... I.e. if we take plastic having volume 2 cubic meter & gold having volume 1 cubic meter we will find mass of gold is far more compared to that of plastic.. Thus, density refers how much tightly the molecules of a substance are bonded together.
Select the correct answer from the drop-down menu. a scientist digs up sample of arctic ice that is 458,000 years old. he takes it to his lab and finds that it contains 1.675 grams of krypton-81. if the half-life of krypton-81 is 229,000 years, how much krypton-81 was present when the ice first formed? use the formula n = n0 . the ice originally contained grams of krypton 81.
The original mass of krypton 81 that is present in the ice is 6.70 grams.
How do we calculate original mass?Original mass of any substance will be calculated as below for the decomposition reaction is:
N = N₀(1/2)ⁿ, where
N = remaining mass of krypton-81 = 1.675g
N₀ = original mass of krypton-81 = ?
n will be calculated as:
n = T/t, where
T = total time period = 458,000 years
t = half life time = 229,000 years
n = 458,000/229,000 = 2
Now putting all these values on the above equation, we get
N₀ = 1.675 / (1/2)²
N₀ = 6.70 g
Hence required mass is 6.70 g.
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