Answer:
0.4
Explanation:
Given parameters:
Mass of NaCl = 0.564g
Mass of KCl = 1.52g
Mass of LiCl = 0.857g
Unknown:
Mole fraction of KCl = ?
Solution:
First, find the number of moles of the given species;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of KCl = 39 + 35.5 = 74.5g/mol
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Molar mass of LiCl = 7 + 35.5 = 42.5g/mol
Number of moles of KCl = [tex]\frac{1.52}{74.5}[/tex] = 0.02mol
Number of moles of NaCl = [tex]\frac{0.564}{58.5}[/tex] = 0.0096mol
Number of moles of LiCl = [tex]\frac{0.857}{42.5}[/tex] = 0.02mol
Sum of moles = 0.02mol + 0.0096mol + 0.02mol = 0.0496mol
Mole fraction of KCl = [tex]\frac{0.02}{0.0496}[/tex] = 0.4
Answer:
.4
Explanation:
Which statement describes the reason for removing the insulation from the
ends of the wires used to make an electromagnet?
A. the ends of the wires become magnetic when the insulation is removed
B. The wires are easier to handle after insulation has been removed from them
C. The metal of the wires must be in contact with the terminals of a battery
D. the insulation on the wires causes the direction of an electric current to reverse
Answer:
The answer is different for other people so look out.The answer here is C. The metal of the wires must be in contact with the terminals of a battery.
Explanation:
I took the quiz.
The metal of the wire must be in contact with the terminals of a battery so that, electrons can easily pass through and generate the electrical current.
What is electrical insulation?An electrical insulation is used to prevent the passage of electricity through an object. The materials which does not conduct electrically at any condition is called insulators.
Insulators are used as protective envelopes over the conducting bodies to resist the electrical shock and shortage of electricity. The electrical wires of circuits are coated with insulating plastics throughout up to the terminals.
The terminals cannot be insulated because, the passage of electricity to external circuit can only be achieved by conducting ends otherwise insulation will resist the passage of electrons to the battery. Thus, option C is correct.
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What do you notice when you get into a car that has been sitting in the sun for a while?
Why is the inside of the car so hot?
How would things be different if the car’s windows were left open?
Answer:
I notice that it's extremely hot after it has been sitting in thr sun for a while. The sun's rays have been directly shining on the car because the car was in the sun's Ray's directly. If the car's windows were to be left open, it would be less hot but still be hot if the rays of the sun were directly on the car.
What is a segment of DNA that can code for?
Answer:
gene
Explanation:
DNA is divided into functional units called genes. A gene is a segment of DNA that codes for a functional product (mRNA, tRNA, or rRNA). Since the vast majority of genes are transcribed into mRNA and mRNA is subsequently translated into polypeptides or proteins, most genes code for protein synthesis
Answer:
coding for protein are called exons, and the noncoding regions separating the exons are called introns. Following transcription, these coding sequences must be joined together before the mRNAs can function. The process of removal of the introns and subsequent rejoining of the exons is called RNA splicing.
Explanation:
An object with a mass of 20.0 kg has a force of 5.0 Newton's applied to it. What is the resulting acceleration of the object?
Answer:
1/4
Explanation:
force/mass
5/20=1/4 abs
What is the electron configuration for an atom on Period #3 and in Group #17?
1s22s22p63523p64523d
1s22s22p?
1s22s22p 3s23p
1s22s22p
p64523d5
Answer:
the answer the question is 2,8,7
A biology experiment requires the preparation of a water bath at 37.08C (body temperature). The temperature of the cold tap water is 22.08C, and the temperature of the hot tap water is 55.08C. If a student starts with 90.0 g cold water, what mass of hot water must be added to reach 37.08C
Answer:
75 g
Explanation:
[tex]m_1[/tex] = Initial mass of water = 90 g
c = Specific heat of water
[tex]\Delta T_1[/tex] = Initial temperature difference = [tex](37.08-22.08)^{\circ}\text{C}[/tex]
[tex]m_1[/tex] = Mass of water to be added
[tex]\Delta T_2[/tex] = Final temperature difference = [tex](37.08-55.08)^{\circ}\text{C}[/tex]
Since, heat energy in the system is conserved we know
[tex]m_1c\Delta T_1+m_2c\Delta T_2=0\\\Rightarrow m_1c\Delta T_1=-m_2c\Delta T_2\\\Rightarrow m_2=-\dfrac{m_1\Delta T_1}{\Delta T_2}\\\Rightarrow m_2=-\dfrac{90(37.08-22.08)}{37.08-55.08}\\\Rightarrow m_2=75\ \text{g}[/tex]
The mass of water to be added to reach the desired temperature is 75 g.
One method for separating polypeptides utilizes their different solubilities. The solubility of large polypeptides in water depends upon the relative polarity of their R groups, particularly the number of ionized groups. The more ionized groups there are, the more soluble the polypeptide. Which of each pair of the polypeptides that follow is more soluble at the indicated pH?
a. (Phe-Met)3 or (Glu)m at pH 7.0
b. (Lys-Ala)3 or(Gly)m at pH 7.0
c. (Ala-Ser-Gly)5 or (Asn-Ser-His)5 at pH 6.0
d. (Ala-Asp-Gly)5 or (Asn-Ser-His)5 at pH 3.0:
Answer:
The definition has been defined throughout the clarification segment below, as per the provided case.
Explanation:
Polypeptides were essential amino acids although therefore realize that those acids become charged individually, provide various R groups but have specific isoelectric positions as well.
The polypeptides could be divided by analysis of multiple isoelectric points including fulfilling the following, even though a protein always at the isoelectric point seems to have the end up losing money.
At pH 7, it would be very negatively (-) charged, although (Phe-Met)₃ is even less positive and therefore less reversible. This would be strongly positively (+) charge (equatorial) around pH 7, except for the amino as well as carboxyl-terminal, then (Gly)₂₀ which again is hourly rounding. Although the carboxylate categories of Asp compounds become partly protonated although neutral throughout (Ala-Asp-Gly)₅, around pH 3, although the imidazole categories of His compounds become completely protonated although covalently bonded throughout (Asn-Ser-His)₅.About pH 6.0, only certain polymers provide covalent bonds of polar Ser, however (Asn-Ser-His)₅ does have side bonds of polar Asn as well as partly protonated peptide bonds of His.Consider the reaction below. Which species is(are) the Brønsted-Lowry acid(s)?
HF (aq) + NHâ (aq) â NHâ⺠(aq) + Fâ» (aq) g
Answer:
HF is the acid
Explanation:
The Brønsted-Lowry theory defines the acids and bases in chemistry as follows:
An acid is the species that can donate a proton
A base can accept protons.
In the reaction:
HF(aq) + NH₃(aq) → NH₄⁺(aq) + F⁻(aq)
As you can see, HF can donate its proton to produce F⁻: HF is the acid
In the same way, NH₃ is accepting a proton, NH₃ is the base.
When comparing the proper position for spotting different exercises, you can conclude that, in spotting any exercise, it is important to __________. A. stand with your feet together B. keep your hand on the bar C. keep your back upright D. Place your hand inside the lifter's hands Please select the best answer from the choices provided. A B C D
Answer:
The answer is B
Explanation:
I took the test. PS... if your taking this test in college you should know it. I'm taking this test in middle school and got a 100%
Exercising is an essential part of the body's daily rouging and hence its necessary to keep the position of the body straight when standing and spotting the exercises.
The person should adopt the proper mechanism of exercising and a proper formal way of doing it. They should focus on posture when standing and sitting.Hence the option C is correct.
Learn more about the proper position for spotting different exercises,
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A chemistry student named Igor was performing a titration experiment. He used 500mL of 6M sulfuric acid, H2SO4(aq) to completely neutralize a 2.00 L solution of unknown concentration sodium hydrodixe, NaOH(aq). What is the concentration of the NaOH(aq) in molarity (M)?
Answer:
3 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
H2SO4 + 2NaOH —> Na2SO4 + 2H2O
From the balanced equation above, the following data were obtained:
Mole ratio of the acid, H2SO4 (nA) = 1
Mole ratio of the base, NaOH (nB) = 2
Next, the data obtained from the question. This include the following:
Volume of acid, H2SO4 (Va) = 500 mL
Molarity of acid, H2SO4 (Ma) = 6 M
Volume of base, NaOH (Vb) = 2 L
Molarity of base, NaOH (Mb) =?
Next, we shall convert 2 L to millilitres (mL). This can be obtained as follow:
1 L = 1000 mL
Therefore,
2 L = 2 L × 1000 mL /1 L
2 L = 2000 mL
Thus, 2 L is equivalent to 2000 mL.
Finally, we shall determine the molarity of the base, NaOH. This can be obtained as follow:
Volume of acid, H2SO4 (Va) = 500 mL
Molarity of acid, H2SO4 (Ma) = 6 M
Volume of base, NaOH (Vb) = 2000 mL
Mole ratio of the acid, H2SO4 (nA) = 1
Mole ratio of the base, NaOH (nB) = 2
Molarity of base, NaOH (Mb) =?
MaVa / M Vb = nA/nB
6 × 500 / Mb × 2000 = 1/2
3000 / Mb × 2000 = 1/2
Cross multiply
Mb × 2000 × 1 = 3000 × 2
Mb × 2000 = 6000
Divide both side by 2000
Mb = 6000 /2000
Mb = 3 M
Thus, the molarity of the base, NaOH is 3 M.
A box has dimensions: l = 10.0 cm; w = 5.0 cm; h = 2.5 cm determined by a mm ruler. Calculate
the volume of the box ± its absolute uncertainty.
Answer:
Volume of box = 125 cm³
Explanation:
Given:
Length l = 10 cm
Width b = 5 cm
Height h = 2.5 cm
Find:
Volume of box
Computation:
Volume of box = lbh
Volume of box = 10 x 5 x 2.5
Volume of box = 125 cm³
what will happen to the sugar when mixed to liquid?
Answer:
Heres the answer.
Explanation:
When you stir a spoonful of sugar into a glass of water, you are forming a solution. This type of liquid solution is composed of a solid solute, which is the sugar, and a liquid solvent, which is the water. As the sugar molecules spread evenly throughout the water, the sugar dissolves.
which issue is a limitation of using synthetic polymers
Answer: As trash, Synthetic Polymers are not biodegradable. Landfills can easily fill up with synthetic polymers. Plastics can be made into different products. Recycling synthetic polymers is costly.
Explanation: Hope this helps in any way possible!
The main issues of using synthetic polymers include toxicity poor biocompatibility etc. Synthetic polymers stay non-degradable for ling time and make the surface polluted.
What are synthetic polymers?Natural polymers are naturally made substances such as cellulose, starch, glycogen etc. Polymers made by man are called synthetic polymers. Synthetic polymers are diverse and are made through several polymerization techniques.
PVC, polyethylene, polyesters Teflon etc. are very common polymers in daily life. A major class of synthetic polymers include plastics which are major pollutants nowadays.
Most of the synthetic polymers are non-biodegradable and will cause landfill issues. Some them are toxic in nature and might cause several health issues. Blending them with biodegradable polymers is a solution for this.
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What is the relationship between atomic size and bond length for H2O / H2S and CO2 / CS2?
5. A sample of methane has a volume of 225 mL at 0.650 atm of pressure. What will the new volume be if the
pressure is increased to 1.25 atm?
Answer:
not sure
Explanation:
Which statement is a scientific law?
Scientists use genes to explain why evolution happens.
Genes are long patterns that are similar to computer codes.
A person’s traits are controlled by different forms of a gene.
The discovery of genes changed how scientists think about life.
**PLEASE heLP i NEED THESE ANSWERSSSSSSSS*
1. What process occurs along transform fault plate boundary?
Answer:
hope it helps...
Explanation:
Along the third type of plate boundary, two plates move laterally and pass each other along giant fractures in Earth's crust. Transform faults are so named because they are linked to other types of plate boundaries. The majority of transform faults link the offset segments of oceanic ridges.
For the chemical reaction 2 HBr(aq) + Ba(OH), (aq) — 2H20(1) + BaBr, (aq) write the net ionic equation, including the phases. net ionic equation:
Answer:
2hbr(aq) + ba(OH)2 (aq) --.> 2 H20 (l) + Babr2 (aq)
ionic equation is follows
2H^+(aq) + 2Br^- (aq) + Ba^2+(aq) + OH^-(aq) --->2H2O(l) + Ba^2+(aq) + 2Br-(aq)
cancel the spectator ions in equation above, that is Ba^2+ and 2Br^- ions
the net ionic equation is therefore=
2H^+(aq) + OH^-(aq)---> 2H2O (l)
Which of these is most likely observed during winter weather?
Cumulonimbus clouds
Explosive sounds
Freezing rain
Water spouts
Please Help!
Answer:
FREEZING RAIN
Explanation:
Answer:
C. freezing rain hope it helps :)
Explanation:
A neutron has what kind of charge?
Answer:
Neutrons have no charge.
Explanation:
Remember it this way Neutral (neither of any side, in this case, + or +) and Neutron both have N. so Neutron is Neutral
How many moles of sodium chloride are present in 0.5 L of 4 Molar NaCl(aq)
Select one:
O a. 2 moles
O b. 3 moles
c. 8 moles
d. 0.25 moles
Answer:
the answer is c.
Explanation:
The number of moles of sodium chloride present in 0.5 L of 4 Molar NaCl(aq) is 2 moles. The correct option is a.
What are moles?Moles are the quantity or amount of any substance. It is a measurement quantity.
The concentration of NaCl is 4 molar
The volume of the solution is 0.5 L is given.
To calculate the number of moles, we use the formula of molarity, in which moles are divided by the volume of the given solution. The formula is:
Molarity = moles/ volume
4 M = moles / 0.5 L
Putting the values in the given formula:
Moles = 4 x 0.5 L = 2 moles
Thus, the correct option is a. 2 moles is the number of moles of sodium chloride.
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The pictures show a rock changing over time.
What process best describes what is happening to this rock?
weathering by acid rain
weathering by plant roots
weathering by water and ice
weathering by wind
Answer:
can you show the picture
Which number completes the balanced chemical equation showing the process of rusting?
4Fe + 3O2 ---> ____Fe2O3
A. 1
B. 2
C. 4
D. 12
Answer:
B. 2
Explanation:
HAPPYYYY TURKEY BREAK
Answer:
2
Explanation:
Number the elements sodium, magnesium, phosphorus, and chlorine in the predicted order ionization energies from the highest to the smallest. sodium magnesium phosphorus chlorine
Answer:
It goes 4 3 2 1
Explanation:
Alphabetical order
Answer:
4- sodium, 3-magnesium, 2-phosphorus, 1-chlorine
Explanation:
edge!
Objects that conduct electricity can easily carry an electrical charge. Which of the following materials best conducts electricity?
A. copper wire
B. plastic tubing
C. rubber sheets
D. cotton string
Answer:
copper wire!
Explanation:
Each copper atom has lost one electron and become a positive ion. ... The electrons can move freely through the metal. For this reason, they are known as free electrons. They are also known as conduction electrons, because they help copper to be a good conductor of heat and electricity. Copper, Silver, Aluminum, Gold, Steel and Brass are common conductors of electricity. When properly installed, it is the safest and most efficient metal to produce electricity. Copper is commonly used as an effective conductor in household appliances and in electrical equipment in general. Because of its low cost, most wires are copper-plated. For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity.
Polymerization is most directly responsible in determining which structure of a protein?
A. quaternary
B. secondary
C. tertiary
D. primary
Answer:
primary
Explanation:
polymerization joins amino acids, often creating a primary structure
Which statement about Fe is supported by the modern atomic theory but not John Dalton’s theory?
A. The element iron is composed of small particles called atoms.
B. The electrons of iron have probable locations in a region of space around the nucleus.
C. Iron atoms combine with other atoms in whole number ratios to form compounds.
D. Chemical reactions that involve iron do not create new atoms of iron.
Answer:
The correct option is B
Explanation:
One of the claims of John Dalton's atomic theory is that atom is the smallest unit of matter (which suggests that there are no particles smaller than an atom in any matter). This claim has been disproved by the modern atomic theory which established that there are particles smaller than atom (called subatomic particles). These particles are electrons, protons and neutrons.
One of the modern atomic theory was by Neils Bohr, who proposed that electrons move in circular orbits around the central nucleus. Thus, the electrons of iron can also be said to be present in a region of space (circular path) around the nucleus. This proves that option B is the correct option as John Dalton's theory did not even recognize the electron(s) nor the nucleus.
Answer:
b
Explanation:
Anyone know how to do this please!! ? I will mark brainlist
Choose the formula for hydroxide.
OH
HPO4
Ca(OH)2
d Ba(OH)2
Answer:
OH
Explanation:
Hydroxide is a diatomic anion with chemical formula OH⁻.
Round each number to two significant figures. 0.002353
Answer:
0.0024
Explanation:
you dont count the zeros as significant factors then round up 3 to 4 because you always round up if its 5 dont worry about the other numbers you dont need them hope it helped