Answer:
C Qualitative Analysis.
Explanation:
Which of the following is a buffer system?
A. NaCl and NaNO3
B. H2CO3 and KHCO3
C. HCl and NaOH
D. H2O and HCl
E. NaCl and NaOH
Answer:
B. H2CO3 and KHCO3
Explanation:
The buffer system is a system in which the solution deny for change in the ph level i.e. at the time when the acid is added to it. It can be made either in a weak acid and salt or can be a weak base and its salt. Now when the acid is added to a buffer so the ratio is not impacted due to which it does not change sufficient for pH level
As per the given options, the third one is correct as the H2CO3 denotes a weak acid and the KHCO3 represents the salt. And these two solution does not create any change in the level of pH
Therefore the option B is correct
Which of the following is a description of an exothermic reaction?
A. releases heat
B. reactants have less enthalpy than the products
C. ∆H is positive
D. gets cold
A description of an exothermic reaction is it releases heat. The correct option is A.
What is an exothermic reaction?An exothermic reaction is a reaction in which heat is released into the atmosphere. In these reactions, less energy is needed to start the reaction and the energy is released when bonds are made in the products. Delta H is always negative in these reactions.
Energy is always given off when the reaction happened, in the form of heat and light. Examples are burning of wood, melting of ice, combustion, corrosion, etc.
Thus, the correct option is A. releases heat regarding a description of an exothermic reaction.
Learn more about exothermic reaction, here:
https://brainly.com/question/18523044
#SPJ5
What determines the shape and function of a protein?
The shape and function of a protein are primarily determined by its three-dimensional structure, which is a result of its primary, secondary, tertiary, and quaternary structures.
Primary Structure: The primary structure of a protein is the linear sequence of amino acids that make up the polypeptide chain. The sequence is dictated by the genetic information encoded in the DNA of the gene that corresponds to the protein. Each amino acid in the sequence is represented by a specific codon in the DNA, and this sequence of amino acids forms the backbone of the protein.
Secondary Structure: The secondary structure refers to the local spatial arrangement of the polypeptide backbone, which is stabilized by hydrogen bonds between amino acids. The two most common secondary structures are alpha-helices and beta-sheets. These structures are important for the stability and folding of the protein.
Tertiary Structure: The tertiary structure is the three-dimensional folding of the entire polypeptide chain, including the secondary structure elements. Various interactions, such as hydrogen bonds, disulfide bridges, ionic interactions, hydrophobic interactions, and van der Waals forces, play a crucial role in stabilizing the tertiary structure. This folding brings distant parts of the polypeptide chain close together, contributing to the unique shape of the protein.
Quaternary Structure: Some proteins are composed of multiple polypeptide subunits, and the way these subunits come together forms the quaternary structure of the protein. The interactions between the individual subunits contribute to the overall structure and function of the complex protein assembly.
Learn more about protein from the link given below.
https://brainly.com/question/33861617
#SPJ6
help whats 2+2 i really don't know what the answer is i think it 1,250 but idk
Answer:
its 4
Explanation:
Answer:
4 is the answer
Explanation:
2 fingers plus 2 fingers is 4 fingers, Not 1,250
You left a glass full of water by a window in your house in the morning. Three hours later you walk by the glass, and the water level is significantly lower than it was in the morning. You have made the observation that the water level in the cup is lower. Then, you ask the following question: “Why is the water level in the cup lower?” What is a possible hypothesis you could make?
Over the course of many years, a rural farm town becomes more urban. Which of the following will most likely happen in the town as a result of this urbanization?
Answer:
Explanation:
Rivers may be contaminated by sewage.
I do hope I helped you! :)
3-An analysis that determines the relative amounts of analytes in numerical terms
A) Quantitative Analysis
B) Qualitative Analysis
C)Quantitative Synthesis
D) Qualitative Synthesis
Q1-(30 Marks) Choose the correct answer
Answer:
A.
Explanation:
Quantitative analysis.
Consider a closed container of gas that is a mixture of 30% CO2 and 70% N2 at room temperature 20°C. The gases are in thermal equilibrium with one another. a) Which has the higher kinetic energy, the average CO2 or N2 molecule? b) What is that root-mean-square velocity of a CO2 molecule? For reference, a carbon atom has 6 protons, a nitrogen atom has 7 protons, and an oxygen atom has 8 protons.
Answer:
a. the kinetic energy will be the same.
b. [tex]\mathbf{\overline v = 407.65 \ m/s}[/tex]
Explanation:
The kinetic theory deals with how the arrangement of particles of a substance determines the properties that substance will possess and the state in which it is likely to be found under a given set of conditions. From the postulates of the kinetic theory of gases, The average kinetic energy of the gas molecules is a measure of the temperature of the gas molecules, This implies that the kinetic energy is dependent on the temperature.
i.e
[tex]K.E = \dfrac{3}{2} \ KT[/tex]
where ;
K = Boltzmann Constant
Since the given gases are in thermal equilibrium, therefore, the kinetic energy will be the same.
b).
The root mean square velocity of CO2 molecule is represented by the equation :
[tex]\overline v = \sqrt{\dfrac{3RT}{M_m}}[/tex]
[tex]\overline v = \sqrt{\dfrac{3\times 8.314 \ J/K /mole \times (293.15 \ K ) }{44 \times 10^{-3} \ kg / mol}}[/tex]
[tex]\overline v = \sqrt{\dfrac{7311.7473 }{44 \times 10^{-3} }}[/tex]
[tex]\overline v = \sqrt{166176.075 \ m/s}[/tex]
[tex]\mathbf{\overline v = 407.65 \ m/s}[/tex]
Given that the specific heat of chromium is 0.455J/g∙K find the final temperature after 35.9J of energy is removed from 11.7g of chromium at 28.5°C.
Answer:
[tex]T_2=35.2\°C[/tex]
Explanation:
Hello,
In this case, since the heat is computed in terms of mass, specific heat and temperature as follows:
[tex]Q=mCp(T_2-T_1)[/tex]
In such a way, for the given heat, we obtain the following temperature:
[tex]T_2=T_1+\frac{Q}{mCp}\\ \\T_2=28.5\°C+\frac{35.9J}{11.7g*0.455\frac{J}{g\°C} }\\ \\T_2=35.2\°C[/tex]
Best regards.
The density of silver is 10.5 g/cm3. What is the mass (in kilograms) of a cube of silver that measures 0.94 m on each side?
Answer:
8721.132 Kg.
Explanation:
The following data were obtained from the question:
Density (D) of silver = 10.5 g/cm³
Length (L) of silver = 0.94 m
Mass (m) of silver =.?
Next, we shall determine the volume of silver. This can be obtained as follow:
Volume = Length × Length × Length
Volume = L × L × L
Volume = L³
Length (L) of silver = 0.94 m
Volume (V) of silver =?
Volume (V) of silver = 0.94³
Volume (V) of silver = 0.830584 m³
Next, we shall convert 0.830584 m³ to cm³. This can be obtained as follow:
1 m³ = 1×10⁶ cm³
Therefore,
0.830584 m³ = 0.830584 m³ / 1 m³ × 1×10⁶ cm³
0.830584 m³ = 830584 cm³
Therefore, 0.830584 m³ is equivalent 830584 cm³.
Thus, the volume of the silver is 830584 cm³.
Next, we shall determine the mass of the silver. This can be obtained as follow:
Density (D) of silver = 10.5 g/cm³
Volume of the silver = 830584 cm³.
Mass of silver =.?
Density = mass /
10.5 = mass of silver /830584
Cross multiply
Mass of silver = 10.5 × 830584
Mass of silver = 8721132 g
Finally, we shall convert the mass of silver, 8721132 g to kilogram (kg). This can be obtained as follow:
1000 g = 1 Kg
Therefore,
8721132 g = 8721132 g / 1000 g × 1 Kg
8721132 g = 8721.132 Kg
Therefore, the mass of each cube of silver is 8721.132 Kg
How does accuracy and precision impact your life
Explanation:
Accuracy refers to the closeness of a measured value to a standard or known value. For example, if in lab you obtain a weight measurement of 3.2 kg for a given substance, but the actual or known weight is 10 kg, then your measurement is not accurate. In this case, your measurement is not close to the known value.
Precision refers to the closeness of two or more measurements to each other. Using the example above, if you weigh a given substance five times, and get 3.2 kg each time, then your measurement is very precise. Precision is independent of accuracy. You can be very precise but inaccurate, as described above. You can also be accurate but imprecise.
For example, if on average, your measurements for a given substance are close to the known value, but the measurements are far from each other, then you have accuracy without precision.
A good analogy for understanding accuracy and precision is to imagine a basketball player shooting baskets. If the player shoots with accuracy, his aim will always take the ball close to or into the basket. If the player shoots with precision, his aim will always take the ball to the same location which may or may not be close to the basket. A good player will be both accurate and precise by shooting the ball the same way each time and each time
Which statement describes a property that is unique to metalloids?
Metalloids are shiny.
Metalloids are semiconductive.
Metalloids are solid.
Metalloids are brittle.
Answer:
Metalloids are semiconductive.
Explanation:
Answer: Metalloids are semiconductive.
Which statement correctly compares an atom of an alkali metal with an atom of the alkaline earth metal next to it on the periodic table? aThe alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion. bThe alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion. cThe alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal. dThe alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.
The atom of alkaline earth metal has one more proton and one more electron than the alkali metal that is next to it to the left on the periodic table. Then the atomic number of the alkali metal is one unit less than the atomic number of the alkaline earth metal next to it
Answer:
A) The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.
Explanation:
Let's evaluate each answer.
A: The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.
This means that the alkali metal atom has to lose 1 valence electron to form a +1 ion while the alkaline earth metal atom has to lose 2 valence electrons to form a +2 ion. This is accurate because alkali metal atoms have 1 valence electron while alkaline earth metal atoms have 2, so the statement is correct.
B: The alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion.
This would mean that the alkali metal atom has to lose 2 valence electrons to form a +2 ion, while the alkaline earth metal has to lose 1 valence electron to form a +1 ion. This is incorrect because alkali metal atoms only have 1 valence electron and will become a +1 ion when losing that electron, while alkaline earth metals have 2 valence electrons and will form a +2 ion upon losing them.
C: The alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal.
This would mean that the alkali metal atom would be located one period higher up than the alkaline earth metal atom. This is untrue, because the question states that the alkali metal atom is located directly next to the alkaline earth metal atom, so they have the same amount of electron shells.
D: The alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.
This would mean that the alkali metal atom would be located one period lower on the periodic table than the alkaline earth metal atom. Similar to the previous statement, this is untrue because the question states that they are located directly next to each other, or on the same period.
(Also, I just took this quiz and e2020 says it's right.)
Is it possible to produce a blood type AB from blood type A and B
Answer:
Yes, it is possible to produce a blood type AB from blood type A and B.
Explanation:
If we were to do a hybrid cross and the mother's blood type was A, then her genotypes would be AA and AO. Additionally, if the father had type B blood, his genotypes would be BB and BO. From this, we can tell that the child's genotypes would have to be A, AB, B, O. Since AB is one of the choices, yes, it is possible to produce a blood type AB from blood type A and B.
The only times where you won't be able to produce a child with type AB is if both of the parents have type B blood and type O blood. Or if one parent has type B blood and the another has type O blood. Or if one parent has type AB and the other one has O blood. Or if both parents have type A blood.
which alkene represents the correct starting material phg?
Explanation:
The pH is larger than 7.
The relationship between pH and pOH is
pH + pOH = 14
if something is base, it's pH is greater than 7.
it's pOH is between 0 and 7.
The temperature at which carbon dioxide sublimes is about 195 K. What is this
temperature in units of degrees Celsius?
-78° Celsius is the temperature in units of degrees Celsius.
What is temperature?Temperature is the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius.
195 Kelvin = 195 - 273.15 = -78.15 Celsius.
-78° Celsius is the temperature in units of degrees Celsius.
Learn more about temperature here:
https://brainly.com/question/23411503
#SPJ2
What is an example of a physical change?
A. having less ash than the paper that was burned to form it
B. ice forming and then melting back into water
C. rust having a different identity than the iron it forms on
D. the irreversible reaction of vinegar and baking soda
What one would you guys choose?
Answer:
B is correct answer
Explanation:
Answer:
B.
Explanation:
What particle(s) of an atom would NOT found in the nucleus?
Electrons
proton
neutron
neutrons and electrons
Answer:
Electrons, they circle the nucleus.
A cannonball made of iron has a volume of 110. cm3. What is the mass, in kilograms, of the cannonball?
Answer:
1 cubic centimeter (cu cm) = 0.001 kilogram (kg)
110cm³ =110*0.001=0.11kg
Explanation:
The volume has been the space occupied by the object and substances and uses the derived units. The mass of the iron ball with a volume of 110 cubic centimeters is 0.11kg.
What is volume?
Volume has been the three-dimensional space that an object has been using in space. The volume can be measured differently for the various states of matter in various units. Volume is the physical parameter to measure the states of matter.
The estimation of the volume can be given by density or mass and has been expressed by the various units like liters, milliliters, cubic meters, cubic centimeters, kiloliters, cubic decimeters, gallons, etc.
The unit cubic centimeter can be converted into kilogram (kg) as:
1 cubic centimeter = 0.001 kilogram
Given,
The volume of a cannonball made of iron = 110 cubic centimeters
The unit conversion from cubic centimeter to kg is shown as:
1 cubic centimeter = 0.001 kg
110 cubic centimeters = 0.11 Kg
Therefore, 0.11 kilogram is the mass of a cannonball made of iron.
Learn more about volume, here:
https://brainly.com/question/13807002
#SPJ2
How many moles of calcium are in 5.82g of calcium?
Answer:
0.024951344877489 mole.
Explanation:
y
You bought a new car and estimated that your monthly payment would be $312. However, your actual payment amount is $325. How much error was in your estimate?
PLEASE HELP ME, I HAVE NO IDEA HOW TO DO THIS :(
Lol . same here. If u get any ideas please let me know
Answer:
See the picture you have to write like this
Exactly how many -OH groups are found in a 6 carbon alditol?
Answer:
The number of OH group found in found in a 6 carbon alditol is 6
Explanation:
The structure of a 6 carbon alditol is shown on the first uploaded image
In a compound the elements are _____ together, whereas in a mixture the substances are blended together.
Answer:
bonded
Explanation:
Compounds are two elements bonded together.
A mixture is multiple substances blended together. The substances aren't bonded together and can easily be extracted from each other.
6. Un volumen de 1.0 mL de agua de mar contiene casi 4 x 10-12 g de Au. El volumen total de agua en los océanos es de 1.5 x 1021 L. Calcule la cantidad total de Au (en gramos) existente en los océanos y su valor total en dólares. ( 1 onza = $ 948)
Answer:
The total amount of Au is $ [tex]2.0\times10^{24}[/tex]
Explanation:
Given that,
Mass of 1.0 ml of Au [tex]m=4\times10^{-2}\ g[/tex]
Total volume of water in oceans [tex]V=1.5\times10^{21}\ L[/tex]
We need to calculate the volume in ml
Using given volume
[tex]V=1.5\times10^{21}\times1000\ mL[/tex]
[tex]V=1.5\times10^{24}\ mL[/tex]
We need to calculate the total mass of Au
Using given data
[tex]1\ ml\ volume = 4\times10^{-2}\ g[/tex]
[tex]1.5\times10^{24}\ ml=4\times10^{-2}\times1.5\times10^{24}[/tex]
So, The total mass of Au is [tex]6\times10^{22}\ g[/tex]
The mass will be in ounce,
[tex]Mass=0.035274\times6\times10^{22}[/tex]
[tex]Mass=2.12\times10^{21}\ ounce[/tex]
The total amount of the Au Will be
[tex]Total\ amount=2.12\times10^{21}\times948[/tex]
[tex]Total\ amount=2.0\times10^{24}[/tex]
Hence, The total amount of Au is $ [tex]2.0\times10^{24}[/tex]
Decaying plants and animals are important to an ecosystem because they
A.
cause disease in living organisms.
B.
reduce soil erosion.
C.
recycle oxygen to the air.
D.
return nutrients to the soil.
Answer:
The option D is correct answer.
Decaying pants and animals are important to the ecosystem as they return the nutrients to the soil.
What is an ecosystem?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 system 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 present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
Learn more about ecosystem,here:
https://brainly.com/question/19267717
#SPJ2
The class measured the density of a copper block to be 8.6 +/-0.2 g/cm3 at the 95% confidence interval with a standard deviation of 0.4 g/cm. The true density of copper is 8.96 g/cm3.
a. What is the high and low number of the confidence interval range? Does the true value fall within the confidence interval?
high:
low:
within range?
b. What is the high and low of the standard deviation range? Does the true value fall within the standard deviation?
high:
low:
within range?
Answer: kindly check explanation
Explanation:
Given the following :
Measured density of copper block:
8.6+/-0.2 g/cm3
True density = 8.96g/cm3
Standard deviation = 0.4g/cm
a. What is the high and low number of the confidence interval range?
High : 8.6 + 0.2 g/cm3 = 8.8g/cm³
Low : 8.6 - 0.2 g/cm3 = 8.4g/cm³
Does the true value fall within the confidence interval? NO
Actual density = 8.96g/cm³ doses not lie in between (8.4 - 8.8)g/cm³
B.) High and low of the standard deviation range?
High = 8.6 + 0.4 = 9.0g/cm³
Low = 8.6 - 0.4 = 8.2g/cm³
Value falls within range of the true density value of copper block.
8.96g/cm³ falls in-between (8.2-9.0)g/cm³
There are________
neutrons in the stable isotope of rhenium (Re-
185)
A.134
B.90
C.125
D.110
There are 110 neutrons in the stable isotope of rhenium. The correct option is D.
What are neutrons?A neutron is a subatomic particle that exists in the nucleus of all atoms except simple hydrogen. The name of the particle comes from the fact that it has no electrical charge; it is neutral. Neutrons have a very high density.
With the exception of the single-proton hydrogen nucleus, nuclei require neutrons to be stable. Neutrons are abundantly produced during nuclear fission and fusion.
Through mainly the process of fission, fusion, as well as neutron capture processes, they are a major contributor to the nucleosynthesis of chemical elements within stars.
The element rhenium-185 is made up of 75 protons, 110 neutrons, and 75 electrons. The element rhenium-187 is made up of 75 protons, 112 neutrons, and 75 electrons.
Thus, the correct option is D.
For more details regarding neutrons, visit:
https://brainly.com/question/13131235
#SPJ2
What is a nebula? ...........................
a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
a clouded spot on the cornea causing defective vision.
Hope this helped
Answer:
A cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
Explanation:
What is 2.1 x 10^6 + 6.2 x 10^7 in scientific notation
Answer:
2100000 + 62000000
Explanation:
You move the decimal place to the right or left acording to the exponent (right if the exponent in positive, left of the exponent in negative.) Ex: if you're solving for 6.2*10^7 you move the decimal 7 places to the right.
Hope this helped,
-Kiddoo :)