Answer:
bacterial or toxic please
How would you prepare 500 cm3 of 2.0 M solution of Na2CO3 solution from its anhydrous salt? [C = 12, O = 16, Na = 23
Answer:
The answer to your question is given below
Explanation:
We'll begin by converting 500 cm³ to L. This can be obtained as follow:
1000 cm³ = 1 L
Therefore,
500 cm³ = 500 cm³× 1 L / 1000 cm³
500 cm³ = 0.5 L
Next, we shall determine the number of mole of Na₂CO₃ in the solution. This can be obtained as follow:
Volume = 0.5 L
Molarity = 2 M
Mole of Na₂CO₃ =?
Molarity = mole /Volume
2 = Mole of Na₂CO₃ / 0.5
Cross multiply
Mole of Na₂CO₃ = 2 × 0.5
Mole of Na₂CO₃ = 1 mole
Finally, we shall determine the mass of 1 mole of Na₂CO₃. This can be obtained as follow:
Mole of Na₂CO₃ = 1 mole
Molar mass of Na₂CO₃ = (23×2) + 12 + (16×3)
= 46 + 12 + 48
= 106 g/mol
Mass of Na₂CO₃ =?
Mass = mole × molar mass
Mass of Na₂CO₃ = 1 × 106
Mass of Na₂CO₃ = 106 g
Thus, to prepare the solution, weigh 106 g of Na₂CO₃ and dissolve in 500 cm³ (i.e 0.5 L) of water.
How much mass of water (H₂O) do I need to mass out if I need 2.5 moles for a reaction?
Answer:
45g
Explanation:
Use the Mole = Mass x Mr equation:
Rearrange the above equation to find mass,
Mass = 2.5 moles x 18 (Mr of H₂O) = 45g
Therefore answer is 45g
Answer:
Given
number of moles (n) =2 . 5 mol
R.tc maas of H2O (m) =?
sln
H2O =(1x2+16)
=18g/mol
n=m/mr
m=nxmr
m=2.5x18
m=45g
mass of water is 45g
Mg(OH)2 is a compound. How many different elements are found in this compound?
Ο Α. 1
ОВ. 3 3
O c. 2
Answer:
3
Explanation:
3 different elements are found
Mg - magnesium
O -oxygen
H - hydrogen
'
mark brainliest
Answer: 3
Explanation:
help me with this question
In physical and chemical changes, the number of atoms and weight of the object always stays the same.
In a chemical change, the substance changes into a different substance.
I'm pretty sure this next one is can or can not be seperated, depending on what has been mixed. Not positive tho.
Determine the m/v% of a solution where 5 g of sugar is dissolved in enough water to yield 250 mL of total solution
Answer:
2 %m/v
Explanation:
Step 1: Given data
Mass of sugar (solute): 5 gVolume of solution: 250 mLStep 2: Calculate the %m/v of sugar in the solution
We will use the following expression.
%m/v = mass of sugar/volume of solution × 100%
%m/v = 5 g/250 mL × 100% = 2 %m/v
This means that there are 2 grams of sugar every 100 milliliters of solution.
Explain how one would sort an element according to the properties of a metal, a metalloid, or a nonmetal.
Who kept scientific experiments from being performed in the middle
ages?
A. The Government
B. The Judicial System
C. The Board of Science
D. The Church
Answer:
D. The Church
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Litmus is an example of an indicator, a substance that changes color depending on its pH.
a. True
b. False
Any help?
The Kb for hydroxylamine, HONH2, is 1.1 x 10 -8
. What would be the pH of a solution
prepared by placing 1.34 g of HONH2 in 0.500 L of water?
Answer:
pH = 9.475
Explanation:
Hello there!
In this case, according to the basic ionization of the hydroxylamine:
[tex]HONH_2+H_2O\rightarrow HONH_3^++OH^-[/tex]
The resulting equilibrium expression would be:
[tex]Kb=\frac{[HONH_3^+][OH^-]}{[HONH_2]} =1.1x10^{-8}[/tex]
Thus, we first need to compute the initial concentration of this base by considering its molar mass (33.03 g/mol):
[tex][HONH_2]_0=\frac{1.34g/(33.03g/mol)}{0.500L} =0.0811M[/tex]
Now, we introduce [tex]x[/tex] as the reaction extent which provides the concentration of the hydroxyl ions to subsequently compute the pOH:
[tex]1.1x10^{-8}=\frac{x^2}{0.0811-x}[/tex]
However, since Kb<<<<1, it is possible to solve for [tex]x[/tex] by easily neglecting it on the bottom to obtain:
[tex]x=[OH^-]=\sqrt{1.1x10^{-8}*0.0811}= 2.99x10^{-5}[/tex]
Thus, the pOH is:
[tex]pOH=-log(2.99x10^{-5})=4.525[/tex]
And the pH:
[tex]pH=14-4.525\\\\pH=9.475[/tex]
Regards!
igneous sedimentary, and metamorphic rocks are found at the same cliff side.Which statement is correct?
Answer:
The metamorphic rock and sedimentary rock were already at this location and magma flowed into other rocks
Explanation:
Phosphoric acid is neutralized by potassium hydroxide according to the following reaction:
KOH (aq) + H3PO4 (aq) → K3PO4 (aq) + H2O (1)
What is the concentration of a phosphoric acid solution if 25.0 mL are exactly neutralized by 20.0 mL of 2.000 M KOH solution?
HELP!
The law of conservation of energy states:
A. Energy increases exponentially with times
B. Total energy decreases due to energy output.
C. Energy cannot be created or destroyed.
D. Energy always remains in the same form.
Answer:
C
Explanation:
energy cannot be created or destroyed like solar energy for instance. it is already energy because it comes from the sun and for other reason.
Hope this helps!
It’s worth 50 points! Please help!
Answer:
1) NO2
2) 49.4%
Explanation:
Which statement can be made about the above passage
Answer:
Explanation:
whats the qustion?
what is the name of this structure here please and thanks
Answer:
look at the file that the other person sent
Structure of benzylidene diacetate....
Explanation:
Benzal .....
Molecular Formula: C11H12O4
NEED A AWNSER ASAP PLEASE!!!!
Answer:
2. the second one is the answer
Because it shows both potential and kinetic energy
Students were discussing elements and which one makes up the majority of the Earth's atmosphere. Their responses are listed below.
Student A: Carbon makes up most of the Earth's atmosphere.
Student B: Phosphorous makes up most of the Earth's atmosphere.
Student C: Nitrogen makes up most of the Earth's atmosphere.
Student D: Oxygen makes up most of the Earth's atmosphere.
Which student is accurate in their response?
Answer:
nitrogen
Earth's atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapor, and neon are some of the other gases that make up the remaining 0.1 percent.
Explanation:
Please help!
Karl-Anthony is trying to plate gold onto his silver ring. He constructs an electrolyte cell using his ring as one of the electrodes. He runs this cell for 90.6 minutes at 213.8 mA. How many moles of electrons were transferred in this process?
Answer:
0.012 mole of electron
Explanation:
From the question given above, the following data were obtained:
Time (t) = 90.6 minutes
Current (I) = 213.8 mA
Number of mole of electrons =?
Next, we shall convert 90.6 mins to seconds. This can be obtained as follow:
1 min = 60 s
Therefore,
90.6 mins = 90.6 × 60
90.6 mins = 5436 s
Next, we shall convert 213.8 mA to A. This can be obtained as follow:
1000 mA = 1 A
Therefore,
213.8 mA = 213.8 mA × 1 A / 1000 mA
213.8 mA = 0.2138 A
Next, we shall determine the quantity of electricity used in the process. This can be obtained as follow:
Time (t) = 5436 s
Current (I) = 0.2138 A
Quantity of electricity (Q) =?
Q = it
Q = 0.2138 × 5436
Q = 1162.2168 C
Next, the equation for the reaction.
Au⁺ + e —> Au
From the balanced equation above,
1 mole of electron was transferred.
Recall:
1 faraday = 96500 C = 1 e
Thus,
96500 C of electricity is needed to transfer 1 mole of electron.
Finally, we shall determine the number of mole electrons transferred by the application of 1162.2168 C of electricity. This can be obtained as follow:
96500 C of electricity is needed to transfer 1 mole of electron.
Therefore,
1162.2168 C of electricity will transfer = 1162.2168 / 96500 = 0.012 mole of electron
Thus, 0.012 mole of electron was transferred in the process.
Following are the calculation to the moles of electrons that transferred in the process:
Given
Current flows
time[tex]= 90.6\ min = 90.6 \times 60\ sec= 5436 \ sec\\\\[/tex]
For Step 1:
Calculating the Total charge flown in the given time:
For Step 2:
Charge on a single electron
So:
Following are the calculation to the charges of electrons:
Following are the calculation to the electrons transferred:
[tex]=\frac{(726.38\times 10^{19})}{ (6.023 \times 10^{23})}\\\\= 120.60\times 10^{-4}\ moles\\\\[/tex]
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Why glucose (monosaccharide) and maltose (disaccharide) give positive Benedict test?
Answer:
please give me brainlist and follow
Explanation:
Substance in water + 3 mL Benedict's solution, then boil for few minutes and allow to cool. The common disaccharides lactose and maltose are directly detected by Benedict's reagent because each contains a glucose with a free reducing aldehyde moiety after isomerization.
Glucose and maltose give a positive Benedict test because they have a free carbonyl group to undergo oxidation.
Explanation:
The monosaccharides are sugars that cannot be further hydrolyzed into simpler sugars like glucose, fructose, ma, etc.The disaccharides are sugars that on hydrolysis give two monosaccharide units like sucrose, lactose, maltose, etc.The polysaccharides are sugars that on hydrolysis give more than two monosaccharide units like sucrose, lactose, maltose, etc.Reducing sugars are which have a free carbonyl group that oxidizes into a carboxylic acid and reduces Benedict reagent like glucose, maltose, etc.Non-reducing sugars which don't have a free carbonyl group like sucrose, all polysaccharides, etc.Benedict test is a chemical test performed to test the presence of reducing sugars.The Benedict reagent is a complex made up of sodium citrate, sodium carbonate, and copper sulfate pentahydrate.The positive test for reducing sugar will be the red coloration of the solution due to the formation of copper(II) oxide.So, from this, we can conclude that glucose and maltose give a positive Benedict test because they have a free carbonyl group to undergo oxidation.
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Wch of the following phrases is the best definition of science?
A. Research that determines the behavior of the physical world
B. Observation of the physical world
C. Knowledge that governs the physical world
D. A set of predictions that interpret patterns in the physical world
The distance that is covered by the wave in one second is called
Answer:
The distance that is covered by the wave in one second is called frequency.
Explanation:
What is the name of PbS2
Answer:
Lead sulfide.
Explanation:
One of the methods that scientists can use to determine the toxicity of a chemical compound is to perform a dose-response analysis.
a. True
b. False
Answer:
a. True
Explanation:
Hello there!
In this case, since the dose-response method is crucial concept in toxicology as it exhibits the result of exposures to toxic chemical compounds with changes in body functions or health, this statement is a. True , as this analysis is understood by means of the relationship -the higher the dose, the more severe the response-, and of course, it is based on observed data from controlled experiments in animal, human clinical, or cell studies, in the light of the determination of the toxicity of the analyzed chemical.
Regards!
150. g of aluminum chloride in 0.450 liters of solution, what is the concentration? (any examples are helpful, thank you)
Answer:
2.49 M
Explanation:
Step 1: Given data
Mass of AlCl₃: 150. gVolume of solution: 0.450 LStep 2: Calculate the moles AlCl₃ (solute)
The molar mass of AlCl₃ is 133.34 g/mol.
150. g × 1 mol/133.34 g = 1.12 mol
Step 3: Calculate the molar concentration of AlCl₃
Molarity is equal to the moles of solute divided by the liters of solution.
M = 1.12 mol/0.450 L = 2.49 M
A compound contains 53% Al and 47% O by mass. What
is the empirical formula of this compound?
Answer:
Al2O3
Explanation:
Empirical formula is found by converting percent composition into a mole ratio.
First, assume you have a 100g sample of the substance. This allows you to make your percent composition into grams.
100% = 100g
53% = 53g Al
47% = 47g O
Next, divide each substance's mass by their molar mass. This converts your number to moles.
[tex]53g Al / 27g Al = 1.96 mol\\\\47g O/16g O = 2.93mol[/tex]
Next, divide both mol answers by the smallest number of moles.
[tex]1.96mol/1.96mol = 1\\2.93mol/1.96mol = 1.5[/tex]
Usually, these answers would be your subscripts for your empirical formula. However, we cannot have a decimal subscript, so we will multiply our answers by a factor of 2 to get to a whole number. This gives us 2 moles of Al and 3 moles of oxygen, or a formula of Al2O3.
Considering the definition of empirical formula, the correct answer is the second option: the empirical formula is Al₂O₃.
Definition of empirical formulaThe empirical formula is the simplest expression to represent a chemical compound, which indicates the elements that are present and the minimum proportion in whole numbers that exist between its atoms, that is, the subscripts of chemical formulas are reduced to the most integers. small as possible.
Empirical formula in this caseAssuming a 100 grams sample, the percentages match the grams in the sample. So you have 53 grams of Al and 47 grams of O.
Then it is possible to calculate the number of moles of each atom in the molecule, taking into account the corresponding molar mass:
Al: [tex]\frac{53 grams}{27 \frac{grams}{mole} }[/tex]= 1.9629 moles
O: [tex]\frac{47 grams}{16 \frac{grams}{mole} }[/tex]= 2.9375 moles
The empirical formula must be expressed using whole number relationships, for this the numbers of moles are divided by the smallest result of those obtained. In this case:
Al: [tex]\frac{1.9629 moles}{1.9629 moles}[/tex]= 1
O: [tex]\frac{2.9375 moles}{1.9629 moles}[/tex]≅ 1.5
You cannot have a decimal subscript, so you will multiply our answers by a factor of 2 to get to a whole number:
Al: 1× 2= 2
O: 1.5× 2= 3
Therefore the Al:O mole ratio is 2: 3
Finally, the correct answer is the second option: the empirical formula is Al₂O₃.
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Chromatin consists of long strands of material located within the nuclear membrane.
True
False
(also if u want brainlist's answer this question and ask a random question so u can give me brainlist back , deal? (i just need 2 people to answer and ill pick who gets it))
Answer:
True
Explanation:
A student was directed to convert the mass of a boulder from kg to pounds.
Conversion factor: 1 pound = 454 g
The mass is 22 kg. The student calculated the weight to be 0.048 pounds.
Is this correct? If not, what went wrong?
Answer:
Incorrect
Explanation:
Given that,
The mass of a boulder, m = 22 kg
We need to find the weight of the student in pounds.
We know that,
1 pound = 454 g
or
1 g = (1/454 pounds)
22 kg = 0.022 grams
So,
0.022 grams = [tex]\dfrac{0.022}{454}\ pounds[/tex]
= 0.000048 pounds
The student says the weight is 0.048 pounds. It means he was incorrect.
The following pairs of soluble solutions can be mixed. In some cases, this leads to the formation of an insoluble precipitate. Decide, in each case, whether or not an insoluble precipitate is formed.
a. AlCl3 and K3PO4
b. RbCO3 and NaCl
c. Na2CO3 and MnCl2
d. K2S and NH4Cl
e. CaCl2 and (NH4)2CO3
Answer:
See explanation
Explanation:
Let us see what happens when each solution is mixed;
a) AlCl3(aq) + K3PO4(aq) ------> 3KCl(aq) + AlPO4(s)
A precipitate is formed here
b) RbCO3(aq) + NaCl(aq) -------> This is an impossible reaction hence no solid precipitate is formed here
c) MnCl2(aq) + Na2CO3(aq) → 2NaCl(aq) + MnCO3(s)
A precipitate is formed.
d) K2S(aq) + 2NH4Cl(aq) ------> 2KCl(aq) + (NH4)2S(aq)
No solid precipitate is formed
e) CaCl2(aq) + (NH4)2CO3(aq) → CaCO3(s) + 2NH4Cl(aq)
A solid precipitate is formed
The diagram shows the sun's interior Convection are present in the convection zone Which describes how fluids change as they travel through the convection zone? Convection zone Radiation zone Core O They change to solids near the Sun's surface. They change to solids near the Sun's radiation zone O They become more dense near the Sun's surface. O They become more dense near the Sun's radiation zone
Answer:
C: They become more dense near the Sun's surface.
Explanation:
I got it correct on EDG
I hope this helps!!!!!!!!
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According to convection, the statement which describes how fluids change as they travel through the convection zone is that they become more dense near the Sun's surface.
What is convection?Convection works by areas of a liquid or gas heating or cooling greater than their surroundings, causing differences in temperature. These temperature differences then cause the areas to move as the hotter, less dense areas rise, and the cooler, more dense areas sink.
Often the areas of heating and cooling are fixed, and allow convective cycles or currents to become established. For example, a saucepan of water over a flame may develop convective currents as the water is heated from below, rises to the surface, and cools. Once cooled enough, the water then sinks back to the bottom of the saucepan where the cycle is repeated, and the convective overturning continues.
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