Someone please help!
Answer:
1.281 Latm/molK
Two people are pushing a couch from opposite sides. One person is pushing to the right with a force of N. The other person is pushing to the lell William
4 N. Which of the following best describes the movement of the couch?
A. The couch will move to the left with a force of IN
B. The couch will not move.
C. The couch will move to the right with a force of 7 N
D. The couch will move to the left with a force of 7N
Answer:
The couch will not move because the people are not working together. Maybe if they call someone to help they can make some progress.
What is the definition of a Lewis acid?
A. A Lewis acid accepts an electron pair from a base.
B. A Lewis acid donates a proton to the solution.
C. A Lewis acid accepts a hydroxide from the solution.
D. A Lewis acid donates an electron pair to a base.
Answer:
A. A Lewis acid accepts an electron pair from a base
Explanation:
PLATO
The definition of a Lewis acid is that a Lewis acid accepts an electron pair from a base.
What is a base?
According to the Arrhenius concept, base is defined as a substance which yields hydroxyl ions on dissociation.These ions react with the hydrogen ions of acids to produce salt in an acid-base reaction.
Bases have a pH higher than seven as they yield hydroxyl ions on dissociation.They are soapy in touch and have a bitter taste.According to the Lowry-Bronsted concept, base is defined as a substance which accepts protons .Base react violently with acids to produce salts .Aqueous solutions of bases can be used to conduct electricity .They can also be used as indicators in acid-base titrations.
They are used in the manufacture of soaps,paper, bleaching powder.Calcium hydroxide ,a base is used to clean sulfur dioxide gas while magnesium hydroxide can be used as an antacid to cure acidity.
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What kind of elements separate the metals from the nonmetals on the periodic table of elements?
Answer: Metalloids
Explanation:
The dark “stair step” line on the right side of the periodic table is where the metalloids are. Metalloids “touch” the SSL. (Stair step line)
The metals are to the left of the SSL and the non metals are to the right of the SSL.
What is the molarity of a solution that contains 45 mEq Ca“ per liter?
Answer:
0.0225 M
Explanation:
In one liter of this solution, there are 45 mEq of Ca⁺².
1 mEq of Ca⁺² is equal to 20 mg of Ca⁺. We know this by dividing its molar mass (40) by the charge of the ion (2).
Meaning that 45 mEq of Ca⁺² is equal to (45 * 20) 900 mg of Ca⁺².
Now we convert 900 mg of Ca⁺² into moles, using its molar mass:
900 mg / 1000 = 0.9 g0.9 g Ca⁺² ÷ 40 g/mol = 0.0225 mol Ca⁺²Finally we calculate the molarity of the solution:
Molarity = moles / liters0.0225 mol / 1 L = 0.0225 M8. The protein in a 1.2846-g sample of an oat cereal is determined by a Kjeldahl analysis. The sample is digested with H2SO4, the resulting solution made basic with NaOH, and the NH3 distilled into 50.00 mL of 0.09552 M HCl. The excess HCl is back titrated using 37.84 mL of 0.05992 M NaOH. Given that the proteins in grains average 17.54% w/w N, report the %w/w protein in the sample.
Answer: The %w/w protein in the sample is 15.2 %
Explanation:
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Moles of solute}={\text{Molarity of the solution}}\times{\text{Volume of solution (in L)}}[/tex]
[tex]\text{Moles of} HCl={0.09552\times 50.00}{1000}=0.0047moles[/tex]
[tex]\text{Moles of} NaOH={0.05992\times 37.84}{1000}=0.0023moles[/tex]
[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]
According to stoichiometry :
1 mole of [tex]NaOH[/tex] require 1 mole of [tex]HCl[/tex]
Thus 0.0023 moles of [tex]NaOH[/tex] will require=[tex]\frac{1}{1}\times 0.0023=0.0023moles[/tex] of [tex]HCl[/tex]
moles of HCl used = (0.0047-0.0023) = 0.0024
[tex]NH_3+HCl\rightarrow NH_4Cl[/tex]
1 mole of HCl uses = 1 mole of ammonia
Thus 0.0024 moles uses = [tex]\frac{1}{1}\times 0.0024=0.0024moles[/tex] of ammonia
Mass of ammonia= [tex]moles\times {\text {Molar mass}}=0.0024\times 17g/mol=0.0408g[/tex]
17 g of ammonia contains = 14 g of Nitrogen
Thus 0.0408 g of ammonia contains = [tex]\frac{14}{17}\times 0.0408=0.034 g[/tex] of Nitrogen
Now 17.45 g of Nitrogen is present in = 100 g of protein
Thus 0.034 g of Nitrogen is present in =[tex]\frac{100}{17.45}\times 0.034=0.195g[/tex] of protein
Now % w/w of protein = [tex]\frac{0.195}{1.2846}\times 100=15.2\%[/tex]
Thus %w/w protein in the sample is 15.2%
If the proteins in grains average 17.54% w/w N, the % w/w protein in the sample is 15.2 %.
What is Kjeldahl analysis?It is a process of converting nitrogen present in any compound into ammonium sulfate.
Step1: calculating the moles by the formula of molarity
molarity × volume
M = 0.09552, V = 50.00 mL =0.05 L
Moles of HCl
[tex]0.09552 \times 0.05 = 0.0047\;mol\\[/tex]
Moles of NaOH
[tex]0.05992 \times 0.03784 = 0.0023 \;mol[/tex]
Moles of HCl used is 0.0047 - 0.0023 = 0.0024
Step2: calculating the mass of ammonia
moles × molar mass
[tex]0.024 \times 17\;g/mol = 0.0408\;g[/tex]
Now, 17 grams of ammonia have 14 grams of nitrogen
so, 0.0408 g ammonia have [tex]\dfrac{14}{17} \times 0.0408 = 0.034[/tex]
In 100 g of protein, there is 17.45 g of nitrogen
So, 0.034 g N have [tex]\dfrac{100}{17.45} \times 0.034 = 0.195 g.\\[/tex]
Step3: calculating the % w/w
[tex]\dfrac{0.195}{1.2846} \times 100 = 15.2 \%[/tex]
Thus, the % w/w is 15.2 %
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Can someone help Me PLZZZZZZ
Which of the following is an organism?
A. DNA
B. Nucleus
C. Cytoplasm
D. Prokaryote
Which of the following statements is true concerning triglycerides?
a. they are always saturated molecules
b. they are Alkanes
c. they are made of one fatty acid attached to three molecules of glycerol
d. they are a form of reserve fuel storage
e. they are found in low numbers in living organisms
Answer: d. they are a form of reserve fuel storage
Explanation:
Triglycerides are special type of lipids. They are formed by glycerol with three fatty acid chains. The fatty acid chains can vary in length, they can be saturated or unsaturated with varying composition. It is the most abundant lipid in diet. It is available in plant as well as animal based foods. In case of mammals the triglycerides are stored in the adipose tissue in which they are broken to release energy.
vitamin can act like some thing what are those thing and how?
Answer:
Some nutrients also act as antioxidants. These may be vitamins, minerals, proteins, or other types of molecules. They help the body remove toxic substances known as free radicals, or reactive oxygen species. If too many of these substances remain in the body, cell damage and disease can result.
In the Determination of an Equilibrium Constant lab, you will react acetic acid with ethanol in the presence of sulfuric acid until equilibrium is established. Then, you will titrate the equilibrium mixture with NaOH to determine the acetic acid concentration. Suppose you determine that the added sulfuric acid requires 2.97 mL of NaOH to be neutralized in a blank solution. The equilibrium mixture requires 12.92 mL of NaOH to reach the endpoint. What volume of NaOH should you use to calculate the acetic acid concentration at equilibrium
Answer:
9.95mL is the volume of NaOH that you must use
Explanation:
In the problem, you have in your blanck the presence of an acid as sulfuric acid. That means the blank requires an amount of NaOH to neutraliz its solution.
The volume required for the sample will be:
Volume of the sample - Volume of the blank
Beacuse we don't have to take into account the acidity of the blanck
12.92mL - 2.97mL =
9.95mL is the volume of NaOH that you must useTrue or False
When burning wood in an open system, mass is conserved?
Answer:
False!
Explanation:
The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. For example, when wood burns, the mass of the soot, ashes, and gases equals the original mass of the charcoal and the oxygen when it first reacted.
What is in between the nucleus and electrons of an atom?
Answer:
The empty space between the atomic cloud of an atom and its nucleus is just that: empty space, or vacuum. ... Electrons are thus 'spread out' quite a bit in their orbits about the nucleus. In fact, the wave-functions for electrons in s-orbitals about a nucleus actually extend all the way down into the nucleus itself.
A geologist conducts an investigation to determine the absolute age of a fossil. She then
repeats the procedure three times. Which BEST explains why she repeated the procedure
several times? (SC.6.N.1.1)
It helps her develop better procedures
It improves the accuracy of the results.
She wants all the results to be different.
She has more than one hypothesis to prove.
Answer:
Explanation:
Hehs
Meredith mixes together 5 grams of baking soda and 5 grams of vinegar in a test tube that is not sealed. She then weighs the product and
finds that it weighs 9 grams. Mathew conducts the same experiment, except in a sealed bag. He finds that 5 grams of baking soda and 5
grams of vinegar will result in 10 grams of product. Which of the following might account for their different findings?
O A. Some of the mass was created during the reaction between vinegar and baking soda in the bag.
OB. Some of the mass of the reactants was converted to light.
O C. Some of the mass escaped from the test tube as a gas before it was massed.
OD. Some of the mass from the test tube was destroyed.
Answer:
simple chemistry experiment—adding baking soda to vinegar—seems to challenge the law of conservation of mass.
Some of the mass escaped from the test tube as a gas before it was massed. Hence option C is correct.
What is experiment?Experiment is defined as a process used to confirm or deny a hypothesis, as well as assess the likelihood or effectiveness of a previously untested idea. Additionally, experiments are used by researchers to confirm or refute new or current theories. The structure or mathematical form of a theory can be hinted at by an experiment, and it can also provide proof that the entities involved in our theories actually exist.
Something new is created when vinegar and baking soda are combined. Carbon dioxide gas soon foams up in the mixture. All of the baking soda can be made to react and dissolve into the vinegar solution if enough vinegar is utilized.
Thus, some of the mass escaped from the test tube as a gas before it was massed. Hence option C is correct.
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what do The representative elements include
Answer:
aajajjajajajajajajajajdsjsjjx jajajjajajajajaisjn
Explanation:
Which atom does not contain a noble gas?
Chlorine is a halogen, not a noble gas.
Explanation:The last two groups of the periodic table is named as halogen family and Nobel gas family.
The group 17 is composed of gases collectively called as halogen and it includes the following gases:
Fluorine
Chlorine
Bromine
Iodine
Astatine
Tennessine
The group 18 is composed of elements which are collectively called as Nobel gas and it includes:
Helium
Neon
Argon
Krypton
Xenon
Radon
Oganesson
these are some
Hope this helped!!
2. The ocean contains a variety of minerals and ionic compounds. A scientist isolates a
specific ion from a sample of ocean water and determines that it has 12 protons and 12
neutrons with 10 orbiting electrons.
Answer is in the photo. I can't attach it here, but I uploaded it to a file hosting. link below! Good Luck!
tinyurl.com/wpazsebu
How does light travel through a solid, liquid, gas, and a vacuum?
Light travels in a straight line as a wave. It does not require any medium or material to travel like sound waves which means it can travel in vacuum.The speed of the light from the special theory of relativity is a constant value of 38x10^8m/second
Which substance is not a fossil fuel?
Which of the following describes an exothermic reaction?
O A. AHt, reactants > AHf, products
B. AHF, reactants = AHf, products
O C. AHf, reactants = 0
O D. AHF, reactants < AHt, products
The option A describes an exothermic reaction.
i.e, ΔHt,reactant > ΔHt, product
What is exothermic reaction?The reaction in which energy is release during the formation of reaction is called exothermic reaction.
Mathematically,
ΔHf = ΔH(product) - ΔH(reactant)
For exothermic reaction, ΔHt,reactant > ΔHt, product
So,for exothermic reaction, ΔHf is negative.
Where,
ΔHf = Enthalpy of formation of reaction
ΔH(product) = enthalpy of formation of product
ΔH(reactant) = enthalpy of formation of reactant
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At which point does condensation occur in this water cycle diagram?
The Water Cycle
B
D
OA A
ОВ. В
О с. С
OD. D
Answer: B
Explanation:
A is evaporation. B is condensation. C is precipitation.
Answer:
it would be b
Explanation:
b would be condensation
PLEASE HELP ME!!
CHEMISTRY DIMENSIONAL ANALYSIS SUPER EASY!!
WILL GIVE BRAINLIEST TO THE !!*CORRECT ANSWER*!!
The density of chocolate is 1.325 g/cm^3. How many cups would 20,000 mg of chocolate be?
Answer:
Cup of volume [tex]0.0675[/tex] cubic centimeter is required
Explanation:
Given
Density of the Cup [tex]= 1.325[/tex] g/cm^3
Total weight of the chocolates [tex]= 20,000[/tex] mg or 20 grams
Density is equal to mass divided by volume
Volume of the chocolates
[tex]\frac{1.325}{20} \\= 0.0675[/tex] cubic centimeter
Imagine riding in a car or bus. Describe four uses of petrochemical products that are related to the manufacture or use of motor vehicles.
13. Describe the flow of thermal energy.
Plz help
Answer: Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. ... This energy is usually in the form of low-level thermal energy. Here, low-level means that the temperature associated with the thermal energy is close to that of the environment. hope this helps. Can u pls give me brainliest
Explanation:
Which change absorbs heat?
A. Firing a rifle
B. Freezing water into ice
C. Melting cheese
D. Breaking rocks with dynamite
CAN SOMEONE PLEASE HELP ME LIKE ACTUALLY !
Atlantic Ocean has been expanding for millions of years. This is because of
volcanoes and earthquakes under the ocean.
plate collisions under the oceans.
convergent boundary.
spreading plates on the sea floor.
(つ ◕.◕ )つ Hey there again!
Answer → Last one Spreading Plates on the Sea Floor
✨Hope this helps✨
Why do buffer systems use either a weak acid or a weak base?
Weak acids and weak bases do not react easily.
Weak acids and weak bases are partially dissociated.
Weak acids and weak bases are unaffected by temperature.
Weak acids and weak bases are found in abundance on the earth.
Answer:
Weak acids and weak bases are only partially dissociated.
Explanation:
When a small amount of an acid or a base is added to water (or a solution of some strong acid or base of some certain [tex]pH \![/tex],) the [tex]pH[/tex] of that solution tends to change significantly.
In contrast, when the same amount of acid or base is added to a buffer system of some certain [tex]pH\![/tex], the [tex]pH[/tex] of this system tends to change by a much smaller amount.
Weak acids and weak bases dissociate only partially. That allows the buffer solutions to contain a large reservoir of both the (undissociated) weak acid (or weak base) and the corresponding conjugate ion, while maintaining the required [tex]pH[/tex].
This reservoir of the partially-dissociated weak acid (or weak base) and its conjugate ion allows the buffer system to absorb [tex]\rm H^{+}[/tex] and [tex]\rm OH^{-}[/tex] that were added to the solution without much change to the [tex]pH[/tex].
For example, consider a [tex]1\; \rm L[/tex] buffer solution that initially included [tex]0.1\; \rm mol[/tex] of acetic acid [tex]\rm CH_3COOH[/tex] (a weak acid with [tex]pK_\text{a} = 4.765[/tex]) and [tex]0.1\; \rm mol\![/tex] of sodium acetate [tex]\rm CH_3COONa[/tex]. The [tex]pH[/tex] of this solution would be [tex]4.765[/tex].
In contrast, if a solution of [tex]\rm HCl[/tex] (a strong acid) and an equal amount of [tex]\rm NaCl[/tex] also needs to be [tex]4.765[/tex], only [tex]10^{-4.765}\; \rm mol \approx 0.0000172\; \rm mol[/tex] of each species could be included.
Assume that [tex]0.001\; \rm mol[/tex] of [tex]{\rm NaOH}\, (s)[/tex] is added to the buffer solution of [tex]\rm CH_3COOH[/tex] and [tex]\rm CH_3COONa[/tex]. The quantity of the partially-dissociated weak acid in this solution is much larger than that of the [tex]\rm OH^{-}[/tex] added to the solution.
Only a small portion of the weak base would be consumed.The [tex]pH[/tex] of the solution would likely change by less than [tex]0.001[/tex].
In contrast, assume that [tex]0.001\; \rm mol[/tex] of [tex]{\rm NaOH}\, (s)[/tex] is added to the [tex]1\; \rm L[/tex] solution with [tex]0.0000172\; \rm mol[/tex] of [tex]\rm HCl[/tex] (fully-dissociated) and [tex]\rm NaCl[/tex].
All the [tex]\rm HCl\![/tex] in this solution would be consumed. The [tex]pH[/tex] of this solution would go well above [tex]7[/tex].
Answer:
Weak acids and weak bases are partially dissociate
Explanation:
I took the test and got 100%
how many atoms are in 4 H2PO4
Answer:
7
Explanation:
just add p has 1 o has 4 and h has 2
please help due in 1 hour. This is 7th grade science. & in return I’ll help you on something! 15 points
Answer: MCCCMC
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4. Why does iron corrode faster in salt water?
~My Answer~:
Water is the enabler of fast oxidation of iron so freshwater will also cause rust. However, salt water is a very good conductor (lots of dissociated ions) and so there are a number of electrolysis reactions that tremendously accelerate corrosion in salt water.