Answer: Technician B
Explanation:
Technician B is correct. The freezing point of a substance is the temperature at which the substance changes state from a liquid to a solid.
Technician A is incorrect. On the other hand, the melting point of a substance is the temperature at which the substance changes state from a solid to a liquid.
15 ft is the same as how many yards
nhóm nào gồm tất cả các kim loại tan trong axit sunfuric đặc nóng nhưng không tan trong axit sunfuric loãng là
Answer:Nhóm gồm tất cả các kim loại tan trong axit sunfuric đặc nóng nhưng không tan trong axit sunfuric lo
Al, Cu, Au.
Al, Fe, Cr.
Ag, Fe, Pt.
Ag, Cu, Hg.
Explanation:
how many grams of potassium cyanide would be needed to make a saturated solution for the volumes indicated below? The solubility of potassium cyanide is 50.0g/100ml
A. 0.150L
B. 75.0mL
C. 1.10L
D. 225mL
Help please and thank youu
Answer:
elementos original
set onde
What is the name of the molecule shown below?
A) ethanol
B) ethanal
C) ethanoic acid
D) ethylamine
The name of the molecule shown is Ethanol.
What is Ethanol?Ethanol is a alcoholic substance that is formed from fermentation of glucose in the presence of yeast or microorganisms.
It has a chemical group that have methyl group, hydroxyl group OH which is bonded to carbon atom.
Therefore, The name of the molecule shown is Ethanol.
Learn more about ethanol below.
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For the following reaction of N2O4, the equilibrium constant is 0.593 at a particular temperature.
N2O4(g) ⇌ 2 NO2(g)
If the initial concentration of N2O4 is 0.880M, what are the equilibrium concentrations?
Please show work!
Answer:
"0.583" is the appropriate answer.
Explanation:
Let,
The initial constant of [tex]N_2O_4[/tex] be "C".
Amount of [tex]N_2O_4[/tex] dissociated into [tex]NO_2[/tex] be "x".
now,
[tex]N_2O_4 \rightleftharpoons 2NO_2[/tex]
Initial constant C -
Equilibrium constant C 2x
The Kc is given as:
⇒ [tex]K_c = \frac{[NO_2]^2}{[N_2O_4]}[/tex]
[tex]=\frac{(2x)^2}{C-x}[/tex]
[tex]0.593=\frac{4x^2}{0.88-x}[/tex]
[tex]4x^2=0.593(0.88-x)[/tex]
[tex]4x^2=0.512-0.593\ x[/tex]
[tex]x=0.291[/tex]
hence,
The constant of [tex]NO_2[/tex] will be:
= [tex]2x[/tex]
= [tex]0.583[/tex]
plz answer (g) i will give rating 5 and thanks who answer plz fast
Answer:
Like many common group 2 metal carbonates, magnesium carbonate reacts with aqueous acids to release carbon dioxide and water
MgCO3 + 2 HCl → MgCl2 + CO2 + H2O.
The procedure to obtain pure magnesium chloride from the reaction is as thus
Step 1: Reaction
- Leave the dilute hydrochloric acid in a beaker.
- Add Magnesium carbonate slowly until it is in excess or until no more gas seem to be getting liberated.
Step 2: Filtration
- Filter with filter paper and funnel.
- Filter off the excess magnesium carbonate as magnesium chloride will be in aqueous form (liquid) and will come out with the filtrate. The residue is the excess magnesium carbonate.
Step 3: Crystallization to obtain solid crystals from the filtrate.
- Pour filtrate solution into evaporating dish/basin
- Provide heat using Bunsen burner
- Pour solution into an evaporating basin and heat over a water bath
- Stop heating when crystals start to form
allow water to evaporate until pure crystals remain.
- Dry crystals using absorbent paper or warm oven.
Precautions
- Use personal protective equipment such as gloves, a lab coat and wear eye protection, especially when heating.
- Avoid inhaling unnecessary gases during the whole process.
8. What is the oxidation number of N in KNO3?
Answer:
The oxidation state of N in the KNO3 is +5
Explanation:
Oxidation rules:
1. Oxygen is -2, unless in peroxides.
2. Group 1 metals = +1
3. Group 2 metals = +2
4. If the molecule is neutral, all of the oxidation numbers have to add up to zero.
5. If the molecule is charged, all of the oxidation numbers have to add up to the charge of the molecule.
So, the given formula represents the salt compound formula unit of potassium nitrate: KNO3
The formula unit is uncharged.
From our rules, we know that,
O = -2
And we can find K on the periodic table, in the first group, thus giving it a +1 charge. Now let's put it all together.
K = +1
N = x
O = -2
Let's take into account the number of atoms of each element we have and make an equation since we know everything has to add up to zero since the molecules are neutral.
+1 +x+3 (-2) = 0 (notice we multiplied 3 by -2 because in the formula we have 3 atoms of oxygen with -2 charge each)
x - 5 = 0
x = 5
Therefore, the oxidation number of N in KNO3 is +5.
On a plateau on a heating curve, _____.
phase changes are occurring
no heat is being absorbed
all the absorbed heat is being used to overcome forces of attraction between the particles or molecules and phase changes are occurring
all the absorbed heat is being used to overcome forces of attraction between the particles or molecules
Answer:
On a Plateu on a heating curve phase changes are occuring
Explanation:
The first Phase is melting during which the temrature stays the same while water melts.Other phase changes are freezing sublimation Vaourization condensation and deposition
what is solution, colloid, suspension?
Explanation:
SOLUTION:Solution is a homogenous mixture of two or more substances in relative amounts that can be varied continuously up to what is called the limit of solubility.
COLLOID:A mixture in which one substance is divided into minute particles (called colloidal particles) and dispersed throughout a second substance
SUSPENSION:A suspension is a heterogeneous mixture of a finely distributed solid in a liquid. The solid is not dissolved in the liquid, as is the case with a mixture of salt and water.
what is the molarity of HCL solution that has a density of 1.17g/ml at 25°?
Here, we have been given that;
$ \bf{1 ml}$ = 1.17 g$ \bf{1 l}$ = 1170 gHence, we can note that,
No. of moles of HCL (n) = $ \sf{\frac{1170}{36.5}}$(n) = 32.05
[tex] \\ [/tex]
Thus,
Molarity = 32.05 mg/LHence, molarity of the given solution will be 32.05 mg/L.
Predict what would happen if a scientist added potassium to a dilute acid.
Potassium reacts with dilute hydrochloric acid to give potassium chloride and hydrogen gas. Heating small pieces of Potassium in air results in the substance melting without any flame being seen and turning instantly into a mixture of potassium peroxide and potassium super oxide.
A Potassium Reaction involves a process in which Potassium is mixed with another substance which react to form something else. Reactions are manifested by the disappearance of properties characteristic of Potassium and the appearance of new properties in the new substance or Compound.
The substances initially involved in a reaction are called reactants or reagents. The most important of the Potassium compounds is Potassium chloride (KCl) which is used in the production of fertilizers and chemicals and also as a salt substitute. Other important compounds are Potassium nitrate (KNO3), also known as saltpeter which is used in the production of gunpowder, fertilizers and pyrotechnics and Potassium hydroxide (KOH) is used to make detergents and soaps. Reactions are described with Chemical Formula and Equations.
Calculate the solubility of Maslog at 25€
4 30-0cm of its Saturated solution at that
temperature gave 180g of the anhydrous
C= 12. 0-46. Ma =23
Salt
Answer:
20
Explanation:
calculated saturated solutions
which best describes the relationship between internal energy and thermal energy
Answer:
answer is d on edge
Explanation:
Can someone answer this ASAP?
Carbon has unique bonding characteristics that allow it to
A
form ionic bonds with any atom to form many different molecules.
B
resist bonding with other atoms and remain a pure element.
С
form chains or rings by bonding to itself and other atoms.
D
form ionic salts that make up half of the known salts on Earth.
Answer:
С. form chains or rings by bonding to itself and other atoms.
Explanation:
Carbon is an element in group 4 of the periodic table with unique bonding properties. Carbon posseses 4 valence electrons in its outer shell. This enables carbon to form covalent bonds with the atoms of other elements e.g. nitrogen, phosphorus, oxygen, hydrogen etc.
Carbon can also combine covalently with other carbon atoms i.e. C-C to form long chains and rings in a process called CATENATION. This unique property of carbon makes it the only element that can form so many different compounds.
Which statement accurately describes the evidence that scientists gather using fossils? Check all that apply.
Complete question is;
Which statements accurately describe the evidence that scientists gather using fossils? Check all that apply.
A) The fossil record can be used to date rocks.
B) Living things with many cells have always lived on Earth.
C) Simple organisms are found only in young rocks.
D) Geologists study ancient remains of plants and animals.
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates.
Answer:
A) The fossil record can be used to date rocks
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates
Explanation:
In scientific research, fossils are sometimes referred to as animals and plant. Now, in studying records of fossils, it will be easy to know the length of existence of living things on the Earth. Also, we can be able to identify the manner in which different relationships exists between plants and animals by predicting their lifestyles, location of their habitation e.t.c which can be used to predict the old time climates.
Looking at the options given in relation to the explanation given, options A, E & F are correct
hii pls help me with this ionic equation
Answer:
net ionic equation
[tex]\boxed{ CaCO_3{}_{(s)} + 2H^{+} {}_{(aq.)} \rightarrow Ca^{2+} {}_{(aq.)} + H_2O_{(l)} + CO_2{}_{(g)} } [/tex]
Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is
A.
Answer:
Explanation:
Formula
The current = charge / time
The charge is in coulombs
The time has to be in seconds.
1 minute = 60 seconds
2 minutes = 120 seconds.
charge = 180 coulombs
current = 180 / 120
current = 1.5 amperes.
A sample of hydrogen gas H2 has a volume of 5.0 L and a pressure of 1.0 atm. What is the final pressure in atmospheres if the volume is decreased to 2 L with no change in temperature and amount of gas
Answer:
2.5 atm
Explanation:
P = Pressure
V = Volume
P1V1 = P2V2
1 x 5 = P2 x 2
5 = P2 x 2
Divide both sides by 2
5/2 = P2 x 2/2
P2 = 2.5
What element has the electron configuration 1522s22p63s23p4?
Answer:
Sulphur
Explanation:
1s² 2s² 2p⁶ 3s² 3p⁴
So in total ya got 16 electrons
3===> defines the period
4+12===> defines the group
and boom, there ya got yaself an element called sulphur
All atoms of the same element:
have the same number of atoms
have the same number of protons
have the same number of neutrons
have the same number of electrons
Answer:
have the same number of protons
Hiii please help me for balancing chemical equations:
potassium iodide + chlorine ------> potassium chloride + iodine
Answer:
KI + Cl2 = KCl + I2
Explanation:
hope this helps!!!
Answer:
2KI +Cl₂ → 2KCl +I₂
Explanation:
Potassium ion: K+
Iodide ion: I-
Thus, potassium iodide is KI.
Chlorine exist as a diatomic molecule thus it is written as Cl₂.
Chloride ion: Cl-
Thus, potassium chloride is KCl.
Iodine also exist as a diatomic molecule, thus it is written as I₂.
Write an unbalanced equation:
KI +Cl₂ → KCl +I₂
Now balance by ensuring the number of atoms of each element on each side is the same.
LHS
K: 1 ×2= 2
I: 1 ×2= 2
Cl₂: 2
RHS:
K: 1 ×2= 2
I: 2
Cl: 1 ×2= 2
Thus, the balanced equation is:
2KI +Cl₂ → 2KCl +I₂
What is the percent yield of a reaction?
O A. The difference between measured and calculated amounts
OB.
The amount of produd obtained
amount possible
* 100
C. The amount of product actually obtained in a reaction
D. The amount of product that is possible from a reaction
Answer:
B. The amount of produd obtained/amount possible * 100
Explanation:
In chemistry, the yield of a chemical reaction is the quantity or amount of products obtained in that chemical reaction. It is calculated by using the following formula:
Percentage yield = Actual yield/theoretical yield × 100
- The actual yield is the amount of products got from a chemical reaction
- The theoretical yield is the amount of product got from using the balanced equation (stoichiometry).
which of the following is an example of an arrthenius acid
Answer:
The common examples of Arrhenius acid includes HCl (hydrochloric acid), H2SO4 (sulphuric acid), HNO3 (nitric acid), etc.Oct 21, 2020
Explanation:
If we burn 1 gr of ethyl alcohol (C2H5OH) this will translate into a release of about 50 W of thermal energy of the flame that raise the temperature of the hot and cold reservoirs of a Sterling engine at 55 °C and 95 °C respectively. If at steady state the engine turns at about 240 rpm, its gears are shaped as rings of radius ~2 cm and weigh 50 gr, how efficient (in %) is the transfer of energy via flame?
Answer:
0.116%
Explanation:
efficiency of sterling engine = 1 - ( 55 + 273 )k / ( 95 + 273 ) k
= 1 - ( 328 / 368 ) = 0.10869
Determine how efficient the transfer of energy via flame is
apply this relation ; energy of steady state / energy output ---- ( 1 )
where; energy output = efficiency of sterling engine * energy
= 0.10869 * 50 = 5.4345 J/sec
energy of steady state = 1/2 * I * w^2 ------ ( 2 )
I = moment of inertia of engine = 2 * 10^-5 kgm^2
back to equation 2 :
energy of steady state = 1/2 * ( 2 * 10^-5 ) * ( 240 * 2π / 60 )^2
= 630.88 * 10^-5 J /sec
Input values into equation 1
= [ (630.88 * 10^-5 ) / 5.4345 ] * 100
= 0.116%
Scoring Scheme: 3-3-2-1 Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used
Answer:
The solution has 0.00994 moles of Co[H2O]6Cl2
Explanation:
Complete question: Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used?
mL= 7.95
Step 1: Data given
Concentration of the starting solution = 1.25 M
Starting solution = Co[H2O]6Cl2
Step 2: Calculate molar mass of Co[H2O]6Cl2
Atomic mass of Co = 58.93 g/mol
Atomic mass of H = 1.01 g/mol
Atomic mass of O = 16.00 g/mol
atomic mass of Cl = 35.45 g/mol
Molar mass of Co[H2O]6Cl2 =
1*58.93 + 12*1.01 + 6*16.00 + 2*35.45 = 237.95 g/mol
Step 3: Calculate number of moles
C = n/v
⇒with C = the Concentration of the starting solution = 1.25 M
⇒with n= the number of moles = to be determined
⇒with v = the volume = 7.95 mL = 0.00795 L
n = C * V
n = 1.25 M * 0.00795 L
n = 0.00994 moles
The solution has 0.00994 moles of Co[H2O]6Cl2
Which of the following changes in the state of a substance results in an increase in the entropy?
Gas to solid
Gas to liquid
Liquid to solid
Solid to liquid
Answer:
the correct answer is
D. solid to liquid
Which of these hypotheses cannot be tested?
A. The percentage of salt in ocean water stays the same throughout the ocean.
O B. Doubling the amount of salt in a bread recipe will cause the dough to rise faster.
C. Cooks should use sea salt in recipes instead of regular table salt.
O D. Increasing the amount of salt in salt water will increase the boiling point.
Cooks should use sea salt in recipes instead of regular table salt.
neutral radicals examples
Neutral radicals are always electropositive
some examples of neutral radicals are:-
Ca±±Mg±±Ba ±±Al±±NH4±Hope it is helpful to you
write molecular formula
1)aurric cloride
2)aluminium hydroxide
3)potassium thiosulphate
4)magnesium bicarbonate
5)magnesium sulphate
6)sodium oxide
7)cuprous oxide
8)mercuric oxide
9)calcium nitrate
10)aluminium oxide
11)ferric chloride
12)ammoium oxide
13)silver chloride
14)hydrogen bromide
15)magnesium nitride
16)hydrogen peroxide
17)sodium sulphate
18)ammonium sulphate
19)ferrous sulphate
20)sodium carbonate
21)zinc carbonate
22)calcium silicate
23)zinc carbonate
24)potassium clorate
25)aluminium hydroxide
26)ammonium hydroxide
27)sodium silicate
Okay.
Here's your below answers.
1) AuCl3.
2) Al(OH)3.
3) K2S2O3.
4) Mg(HCO3)2.
5) MgSO4.
6) Na2O.
7) CuO.
8) HgO.
9) Ca(NO3)2.
10) Al2O3.
11) FeCl2.
12) (NH4)2O.
13) AgCl.
14) HBr.
15) Mg3N2.
16) H2O2.
17) Na2SO4.
18) (NH4)2SO4.
19) FeSO4.
20) Na2CO3.
21) ZnCO3.
22) CaSiO3.
23) ZnCO3.
24) KClO3.
25) Al(OH)3.
26) NH4OH.
27) Na2SiO3.
