Answer:
Anna didn't wear a lab coat
Explanation:
The first thing anyone who is to carry out a procedure or an experiment in a lab needs to do when he/she enters a lab is to wear a lab coat. This is a lab safety rule that protects the individual from been affected by spillage that could occur as a result of the experiment been conducted.
From the narration in the question, it is not stated anywhere that Anna wore a lab coat before embarking on her lab procedure.
Answer:
C, wear goggles, anytime chemicals, heat, or glassware are used.
Explanation:
This is the correct answer on the Lincoln learning platform.
What are the properties of alkynes
Calcula el %m/v de alcohol en una mezcla utilizada para la desinfección de manos formada por: 15 ml de agua (densidad=1g/ml), 105 g de etanol (densidad: 0,798 g/ml) y 4,5 gramos de jabón líquido (densidad= 1,5 g/ml)
Answer:
%m/v =70%
Explanation:
El %m/v es una unidad de concentración que se define como cien veces la división entre la masa de una sustancia (En gramos) y el volumen total en el que esta sustancia se encuentra (en mL).
En el problema, debemos hallar la masa de etanol (Alcohol) y el volumen total de la solución.
Masa alcohol:
Ya te la dan en el problema: 105g
Volumen solución:
Volumen agua: 15mL
Volumen etanol: 105g × (1mL / 0.798g) = 131mL
Volumen Jabón líquido: 4.5g × (1mL / 1.5g) = 3mL
Volumen: 15mL + 131mL + 3mL
149mL
Así, el %m/v de alcohol en la solución es:
%m/v = (105g / 149mL) × 100
%m/v =70%
In the lab, Amanda has two solutions that contain alcohol and is mixing them with each other. She uses twice as much Solution A as Solution B. Solution A is 11% alcohol and Solution B is 18% alcohol. How many milliliters of Solution B does she use, if the resulting mixture has 320 milliliters of pure alcohol?
Answer:
1,103.47 milliliters
Explanation:
The total percentage of alcohol from solution A and solution B is 29. In a solution that is a mixture of solution A and B, the percentage of alcohol that would be contributed by solution A would be:--
11/29 x 100% = 37.93%
--while the percentage of alcohol that would be contributed by solution B would be:
18/29 x 100 = 62.07%
Hence, if a mixture of A and B has 320 milliliters of alcohol, the amount of alcohol contributed by B would be:
320 x 62.07/100 = 198.624 milliliters
Now, remember that solution B is 18% alcohol. This means that the 18% alcohol content of solution B is 198.624 milliliters. Thus, the total volume of solution B would be:
198.624 x 100/18 = 1,103.47 milliliters.
Therefore, the total milliliters of solution B Amanda used would be 1,103.47.
formula for soda glass
Answer:
composition of soda-lime glass is 73% SiO2 – 15% Na2O − 7% CaO − 4% MgO − 1% Al2O3 [129,132,133].
The Soda glass formula is SiO2, Na2O, CaO, Al2O3, K2O, SO3, MgO, Fe2O3, TiO2
Soda glass is a chemical compound that stands out for being the most widely used material to make windows, bottles, glasses, among others.
This compound is characterized by being chemically stable, reasonably hard, and extremely versatile because it can be recycled since it can be melted to make new products.
Its chemical formula is made up of other compounds such as:
SiO2, is Silicon OxideNa2O, is sodium oxideCaO, is calcium oxideAl2O3, is aluminum oxideK2O, is potassium oxideSO3, is sulfur oxideMgO, is magnesium oxideFe2O3, is iron oxideTiO2, is Titanium OxideAdditionally, the compounds found in the highest proportion in glass are SiO2 (74 atoms) and Na2O (13 atoms).
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Which fact was most likely discovered between the time of Mendeleev’s table and the time of Moseley’s table that helped Moseley develop his version?
Answer:
The number of protons in an atom is different than the atom’s total mass.
Explanation:
Mendeleev knew only that, with some anomalies, the properties of elements varied periodically with their atomic masses.
Moseley's X-ray experiments enabled him to remove these anomalies and to show that the properties of elements varied with their atomic numbers.
Chadwick later discovered that the mass differences were caused by the presence of neutrons.
compare the activity of sodium and iron with water and dilute acid
Answer:
Reactions of sodium with water and dilute acid
Sodium reacts explosively with dilute HCl(aq) to produce NaCl(aq) and H₂(g)
2Na (s) + 2HCl(aq) → 2NaCl(aq) + H₂(g)
Sodium reacts violently with cold water to produce NaOH(aq) and H₂(g)
2Na (s) + H₂O(l) → 2Na(OH)(aq) + H₂(g)
The produced hydrogen may become ignited and explode
Reactions of iron with water and dilute acid
Iron reacts very slowly with dilute acid to produce iron (II) chloride and hydrogen gas
Fe (s) + 2 HCl (aq) → FeCl₂ (aq) + H₂ (g)
Iron does not react with cold water. Iron reacts only with steam
Explanation:
How many gram of zinc will have to be treated with dilute hydrochloric acid to liberate 1.85 dm³ of hydrogen at 27°C and 750mmHg?
Answer:
Explanation:
given
volume=1.85 d m^3
T=27 degree C=27+273 k=300 k
P=750 mmHg
mass of zinc=?
we know that PV=nRT
n=m/M
PV=mRT/M
M for zinc=65.4
PVM=mRT
m=PVM/RT
m=750*1.85*65.4/0.0821*300
m=90742.5/24.63
m=3684
hope this will help u
100 cm^3 of oxygen diffuses through a Porous in 3second how long will it take 150 cm^3 of sulphur (iv) oxide diffuse through the same pot? ( oxygen= 16 sulphur = 32)
Answer:
3.18 seconds
Explanation:
Given the following :
Volume of oxygen (V1) = 100cm^3
Time taken (t1) = 3 seconds
Volume of Sulphur (iv) oxide (v2) = 150cm^3
From Graham's Law of diffusion:
(r1/r2) = √(m1/m2)
Where r = rate of diffusion
m = molar mass
Note rate (r) = (volume / time)
[(V1/t1) ÷ (v2/t2)] = √(m1/m2)
(v1/t1) * (t2/v2) = √(m1/m2)
m1 = 02 = (16 * 2) = 32
m2 = SO2 = (32 + (16 * 2)) = 64
(100/3) * (t2/150) = √(32/64)
100t2 / 450 = √(32/64)
100t2 / 450 = √32 / 8
100t2 / 450 = √32 / 8
100t2 * 8 = 450 * √32
800t2 = 2545.5844
t2 = 2545.5844 / 800
t2 = 3.1819805
t2 = 3.18 seconds
It will take 3.18s for 150cm^3 of Sulphur (iv) oxide to diffuse through the same pot.
What is ionic bond and explain it
Answer:
An ionic bond is a chemical bonding involving the attraction between oppositely charged ions
Explanation:
On the periodic table, elements from group 1 and 7 are attracted to each other and when they bond, it's called ionic bonding. This is because of their valence electrons and ions.
Answer:
Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds. It is one of the main types of bonding along with covalent bonding.
The pH of a solution decreases by 2.0. How does the hydronium ion concentration of the solution change? Increases to 2 times the original concentration increases to 100 times the original concentration decreases to one one hundredth. Of the original concentration decreases to one half. Of the original concentration
Answer:
The hydronium ion concentration increases to 100 times the original concentration
Explanation:
The pH of a solution is defined as the negative logarithm of the hydrogen or hydronium ion concentration of that solution. It is given by the expression below:
pH = -log[H₃O⁺] = log[H₃O⁺]⁻¹
Assuming the solution was at neutral with original pH = 7;
The new pH of the solution will be = 7 - 2 = 5
At pH = 7;
log[H₃O⁺]⁻¹ = 7
[H₃O⁺]⁻¹ = 10⁷
[H₃O⁺] = 10⁻⁷
At pH = 5
log[H₃O⁺]⁻¹ = 5
[H₃O⁺]⁻¹ = 10⁵
[H₃O⁺] = 10⁻⁵
10⁻⁵ = 10⁻⁷ * 10²
But 10² = 100
Therefore, the hydronium ion concentration increases to 100 times the original concentration
Answer:
B
Explanation:
On Edge
A 46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the four substances whose properties are given, which is the most likely identity of this substance?
THIS IS THE COMPLETE QUESTION BELOW
46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the four substances whose properties are given, which is the most likely identity of this substance?
Substance Density (g/cm3) Melting Point (°C) Boiling Point (°C)
molybdenum 10.28 2,623 4,639
mercury 13.53 -39 357
hafnium 13.31 2,233 4,603
lead 11.34 327 1,749
A.
molybdenum
B.
mercury
C.
hafnium
D.
lead
Answer :
The correct option is OPTION C.
(C) Hafnium
Explanation;:
We were given the mass of substance as (m) = 46.9 g
The Volume of substance as (V) = 3.5 Cm^3
But we know Density of substance.= Mass/it's Volume
Then Density=46.9/3.5
=13.4g/Cm^3
From the questionthe given substance is solid at room temperature, and let us take Mercury as an example , Mercury is liquid at room temperature. ThenMercury cannot be the answer.
Base on the determined density which is 13.4 and the density of Hafnium also is 13.31 g/cm3 and it is solid at room temperature. Therefore, Hafnium is the only likely element here.
if 193 ml of chlorine gas was collected at 21 celsius, what volume would it have if the temperature dropped to 0 celsius
Answer:
New volume of chlorine gas (V2) = 179 ml (Approx)
Explanation:
Given:
Volume of chlorine gas (V1) = 193 ml
Temperature of chlorine gas (T1) = 21°C = 21 + 273 = 294 k
New temperature of chlorine gas (T2) = 0°C = 0 + 273 = 273 k
Find:
New volume of chlorine gas (V2) = ?
Computation:
Using charle's law
V1 / T1 = V2 / T2
193 / 294 = V2 / 273
V2 = 179.21
New volume of chlorine gas (V2) = 179 ml (Approx)
Compound A, C6H12O2, was found to be optically active, and it was slowly oxidized to an optically active carboxylic acid B, C6H12O3, by Ag(NH3)2. Oxidation of A by anhydrous CrO3 gave an optically inactive compound D that reacted with Zn amalgam/HCl to give 3-methylpentane. With aqueous H2CrO4, compound A was oxidized to an optically inactive dicarboxylic acid C, C6H10O4. Give structures for compounds A, B, and C; do not specify stereochemistry.
Answer:
kindly check the attach file for the drawing of the chemical structures.
Explanation:
So, we are going to start from the compound D, which is stated in the question to be optically active. Therefore, we will have that:
STEP ONE: THE OXIDATION OF COMPOUND A, C6H12O2 TO GIVE COMPOUND C.
The oxidation of compound A,C6H12O2 gives another chemical compound that is chemical compound C which is a optical inactive di-carboxylic acid. The chemical equation is given below:
C6H12O2 + H2Cr2O4 --------------------------------------------> HOOCCH2CHCH3CH2COOH.
STEP TWO: THE OXIDATION OF COMPOUND A, C6H12O2 TO GIVE COMPOUND B.
The oxidation of compound A,C6H12O2 gives another chemical compound that is chemical compound C which is a optically active acid. The chemical equation is given below:
C6H12O2 + Ag(NH3)2^+ -----------------------------> C6H12O3.
Since the question asked us to give the structures of Compound A,B and C there is no need to to show the chemical reaction for compound D.
Kindly check the picture below for the chemical structures.
A baseball has a mass of 135 grams and a softball has a mass of 270 grams. In which of the following situations would they have the same momentum? The baseball and softball are thrown at the same speed in the same direction.
Answer:
The baseball is thrown twice as fast as the softball in the same direction.
Explanation:
Over the period of a few days, a hospital receives an overwhelming increase in the number of patients with food poisoning. How would a scientist respond to this increase in sick patients?
Answer:
Hey there!
A scientist would try to determine the cause of the food poisoning, and see if the people who got poisoned had anything in common, for example: they ate at the same restaurant, they are all people of a certain age, etc.
Let me know if this helps :)
does the tendency to gain electrons decrease as we go down grp 17?
Explanation:
Hi, there!!!!
Let me simply clear you..
Yes,The tendency to gain electrons (in nonmetal) decreases when we go down group 17.
The reason for above answer is when we go downwards in periodic table then the atomic size increases with the addition of number of shells and force of attraction between the nucleus and valance shell decreases. The force of attraction between the nucleus and valance shell becomes weaker due to which the force of attracting the electrons gets decreased.
So, we can say that the tendency to gain electrons decreases as we go down in periodic table.
Hope it helps....
16. I don't want to go anywhere apart from
Nairobi.
A. instead
B. only
C. besides
D. than
[tex]\huge\red{AnsweR:}[/tex]
I don't want to go anywhere apart from than Nairobi.
[tex]<font color=orange>[/tex]
A. instead
B. only
C. besides
D. than_______________________
#Be Brainly
When might Accurate length measurement be important?
Answer:
When you are going to measure small lengths or objects or when you are going to measure things with great accuracy.
Explanation:
Tips for memorizing the first 20 elements of the periodic table?
Answer:
hydrant flying with balloon, balloon has lithp letting air out, bee: really yum balloon
= = = =
hydrogen helium lithium beryllium
be bore on the balloon, balloon pops, hydrant drops and makes a car bomb
= =
boron carbon
night row general gets hurt by car bomb nearby, that general gets off boat
=
nitrogen
wearing oxygen mask, mask is full of fluride gel, then he got neon teeth
= = =
oxygen fluorine neon
(try making a story out of the elements, use your imagenation)
I will give u tips to learn whole periodic table
1. Break down the table into sections
2. Spread out the memorisation process
3. Learn the elements in a song
4. Make none sense words made from element symbols
5. Use colour to learn element groups
6. Use mnemonic device to help remember the order of elements
I am sure this will be helpful for uuu
Explanation:
If two solutions with concentrations of 0.4 M sugar and 0.7 M sugar respectively are separated by a semipermeable membrane, during osmosis there is a net flow of Group of answer choices sugar molecules from the dilute to the concentrated solution sugar molecules from the concentrated to the dilute solution water molecules from the concentrated to the dilute solution water molecules from the dilute to the concentrated solution
Answer: Water molecules from the dilute to the concentrated solution
Explanation:
During Osmosis if a solution is separerated by a semipermeable membrane, the solvent (typically water) from the less concentrated solution in terms of solute goes through the semipermeable membrane to the solution with the higher concentration so that the concentrations between the solutions can be balanced.
With the above solutions therefore, water molecules would move from the solution of 0.4M of sugar to the solution with a 0.7M of sugar through the semipermeable membrane.
During osmosis, water molecules move from the dilute to the concentrated solution.
OSMOSIS:
Osmosis is the movement of water molecules from a region of higher concentration (low concentration of solute) to a region of lower concentration (higher concentration of solute). The principle of movement is based on the concentration gradient i.e. difference in concentration across a semipermeable membrane. According to this question, two solutions have sugar concentrations of 0.4 M sugar and 0.7 M respectively and are separated by a semipermeable membrane. Therefore, water molecules will move from the dilute (0.4M) to the concentrated (0.7M) solution during osmosis.Learn more at: https://brainly.com/question/13655668?referrer=searchResults
Which is the correct definition of metallic bonding? Select one: a. an array of positive ions in a sea of electrons b. complete transfer of valence electrons c. atoms share electrons to to be stable
Answer:
I believe it's A) an array of positive ions in a sea of electrons
The reactants of a reaction are 2AgClO3 and Na2CO3. According to the law of
conservation of matter, which of the following could be a product?
O A. NaOH
O B. Ag2CO3
O C. CaCO3
O D. AgNO3
Answer:
The answer is "Option B"
Explanation:
Law:
In the law of the conservation of matter, states the volume of matter throughout the process remains constant. In any particular case, it is closed to the movement of matter. It is mostly on conservation of energy means, that the total mass of the products should consider the sum of the mass, which is the reactant of the event of chemical processes.
Reaction:
[tex]2AgClO_3+ Na_2CO_3= Ag_2CO_3+Na_2ClO_3[/tex]
In the above equation when we react to [tex]2AgClO_3[/tex] from the [tex]Na_2CO_3[/tex], it will give [tex]Ag_2CO_3 \ \ \text{and} \ \ Na_2ClO_3[/tex]. that's why option b is correct.
Answer:
Ag2CO3
Explanation:
What is the equilibrium constant of aA+bB cC +dD?
Explanation:
{c}^C . {d}^D / {a}^A . {b}^B
ocean in ionnic bonding, during the transfer of electrons between two neutrally charged atoms, one electron moves from one atom to another. What are the new relative charges between two atoms
Answer: The new relative charges between two atoms are +1 and -1 for cation and anion respectively.
Explanation:
When an atom accepts an electron, negative charge is created on atom and is called as anion.
When atom loses an electron, positive charge is created on atom and is called as cation.
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Thus when one electron is lost by an atom it forms one positive charge and when one electron is gained by an atom it forms one negative charge.
Foe example: sodium atom loses its one valance electron and form cation [tex]Na^+[/tex]. Chlorine atom gain one electron and form anion [tex]Cl^-[/tex]. they both combine to form sodium chloride through ionic bond.
45. The following data was collected for 3 compounds:
Mass of Nitrogen that combines with 1 g of Oxygen
Compound A 1.750 g
Compound B 0.8750 g
Compound C 0.4375 g
Show whether these are the same or different compounds. What chemical law is being observed here?
Answer:
The three compounds are different compounds
Explanation:
The mass of Nitrogen that combines with 1 gram of Oxygen in Compound A = 1.750 g
The mass of Nitrogen that combines with 1 gram of Oxygen in Compound B = 0.8750 g
The mass of Nitrogen that combines with 1 gram of Oxygen in Compound C = 0.4375 g
According to the law of multiple proportions, when atoms of two different elements react to form compounds, the masses of one of the elements that combines with a fixed mass of the other element are in small whole number ratios.
The ratio of the masses are;
Mass of Nitrogen in Compound B/(Mass of Nitrogen in Compound C = 0.8750/0.4375 = 2
Mass of Nitrogen in Compound A/(Mass of Nitrogen in Compound C = 1.750/0.4375= 4
Mass of Nitrogen in Compound A/(Mass of Nitrogen in Compound B = 1.750/0.8750= 2
Given that the masses of Nitrogen in the three compounds are in small whole number ratios, the three compounds, Compound A, Compound B, and Compound C are different compounds.
how many significant figures are in 820 400.0 L
Answer:
7 significant numbers
Which of the following statements about a chemical reaction is false? Group of answer choices The phases in a chemical reaction tell us the state of the reactants and the products. An individual coefficient, with no reactant or product, in a balanced equation is meaningless. The subscripts in a balanced equation tell us the number of atoms in a molecule.
Answer:
Option B
Explanation:
Let us go through each of the options individually.
option A.
he phases in a chemical reaction tell us the state of the reactants and the products.
This is true because phases representations such as s, l , g and q tells us the state of the reactants if they are in the solid or liquid or gaseous or aqueous state of matter respectively. So this is not our answer.
option B
An individual coefficient, with no reactant or product, in a balanced equation is meaningless.
This option is correct, because in every reaction, there must be the reactant and product present.
option C
The subscripts in a balanced equation tell us the number of atoms in a molecule.
This is correct. Consider the equation below;
2H₂ + O₂ --> 2H₂O
In the reactant phase, the subscripts tells us that we have just two atoms of oxygen present.
In 1838 botanist Matthias Schleiden determined that all plants are composed of cells. In 1839, anatomist Theodor Schwann proposed that all animals are composed of cells. In 1855, biologist Rudolph Virchow added to Schleiden's and Schwann's observations and proposed that all living things are composed of cells. Which statement is also part of Virchow's cell theory?
Answer:
cells arose from preexisting cells
Explanation:
Rudolph Virchow is a German biologist that built on the work of other scientists such as Theodor Schwan to contribute his own quota to the development of the cell theory as it is currently known.
After several studies, Virchow rejected the idea of spontaneous generation and accepted the initially rejected idea of cell division. He earlier believed that cell division only takes place is some special type of cells and not in all cells.
Even though Virchow was not the first to bring the idea of cells arising from preexisting cells, he was the one that popularized the idea and added it to the earlier belief that all living organisms are made up of cells.
Answer:
B
Explanation:
What is the term for the belief that one's own culture is superior to other
cultures?
O A. Cultural behavior
O B. Cultural competence
C. Cultural relativism
D. Cultural absolutism
Cultural absolutism is the term for the belief that one's own culture is superior to other cultures.
What is cultural absolutism?Cultural absolutism is one of the perspectives which is common in anthropology, but it can also be applied to non-scientific thoughts also. It assumes that there is a set of universal values which are objectively valid in every situation.
Today, pure cultural absolutism is seen as a harmful effect of ethnocentrism focusing on the belief that one's own culture is superior and the practice of holding other's cultures to the standard of our own. However, purely relativist anthropologists have also been critiqued for going too far, by denying any common humanity and being too lenient towards morally questionable practices. Contemporary approaches try to find a balance between the universal values, such as human dignity, and a more inclusive and relativistic side of culture.
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#SPJ2
3. How did ethanol use affect the shortage of corn available to consumers during and
after the drought of 2012? Do you think that commodities in one sector should be used
in another economic sector? How might the concept of needs and wants affect your
analysis of this issue?
Due to drought, the production of corn decreases and shortage of it occurs.
Effects of droughtYes, commodities in one sector should be used in another sector because scientist invented methods in which one commodity is used in several sectors for the production of new products.
Corn was used for the production of ethanol which causes the shortage of corn that was available to consumers during and after the drought condition of 2012 so we can conclude that due to drought, the production of corn decreases and shortage of it occurs.
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