Answer:
Sodium Hydroxide turns blue litmus red .
Why LDL called "bad" cholesterol?
Answer:
Its called bad cholesterol because a high LDL level leads to buildup of cholesterol in your arteries.
Explanation:
uppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 1.83 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 22.08 mL. What volume of base was required for the titration?
Answer:
20.25 mL.
Explanation:
The volume of base required for the titration can be derived by removing the base titrant volume from the volume at endpoint.
i.e Final volume - initial volume
= (22.08 - 1.83)mL
= 20.25 mL.
(Repeat and average volume results for accuracy.)
A certain atom has 22 protons and 19 electrons. This atom loses an electron. The net charge on the atom is now ___.If this same
atom with 22 protons and 19 electrons were to gain 3 electrons, the net charge on the atom would be ____
Answer:
I think first one has net charge 4+
second one has earlier 3+ charge after gaining net charge becomes zero
I think this is correct
Explanation:
if wrong means pls correct me bro
An atom has 22 protons and 19 electrons. The net charge on the atom is now elementary, 1e+. If the same atom with 22 electrons and 19 electrons were to gain 3 electrons, the net charge on the atom would be, negative, -3.
What are electrons?Electrons are the positively charged particles that revolve around the negatively charged nucleus. Electrons revolve around the nucleus, and protons and neutrons are also present.
When the electrons gain electron they acquire negative charge and when they donate electrons it acquires positive charge.
It gains 3 electrons that why -3 charge.
Thus, the correct elementary charge, negative, -3.
Learn more about electrons
https://brainly.com/question/1255220
#SPJ2
In the Hall-Heroult process, a large electric current is passed through a solution of aluminum oxide dissolved in molten cryolite , resulting in the reduction of the to pure aluminum. Suppose a current of is passed through a Hall-Heroult cell for seconds. Calculate the mass of pure aluminum produced. Round your answer to significant digits. Also, be sure your answer contains a unit symbol.
The given question incomplete, the complete question is:
In the Hall-Heroult process, a large electric current is passed through a solution of aluminum oxide (Al,03) dissolved in molten cryolite (Na, Alts).re in the reduction of the Al, o, to pure aluminum. Suppose a current of 1800. A is passed through a Hall-Heroult cell for 37.0 seconds. Calculate the mass of pure aluminum produced Be sure your answer has a unit symbol and the correct number of significant digits.
Answer:
The correct answer is 6.2114 grams.
Explanation:
Based on the given question, the value of current or I have given is 1800 amperes, the time given is 37 seconds, and there is a need to find the mass of the pure aluminum generated in the process. Mass or weight can be determined by using Faraday's first law equation, that is, w = MIt/nF.
Here, M is the atomic mass, w is the weight of the substance deposited, t is time, I is current, n is the number of moles of the electron, and F is the Faraday's constant, which is 96500 C. In the process mentioned in the question, aluminum oxide is reduced to give rise to pure aluminum, and in the process 3 electrons are gained. So, the value of n will be 3. The M or the atomic mass of Al is 27 gm per mole. Now putting the values in the equation we get,
w = 27*1800*37 / 3*96500
w = 1798200 / 289500
w = 6.2114 grams
Hence, pure aluminum produced in the process is 6.2114 grams.
A gas sample has a pressure of 2.65 atm when the temperature is -18 ∘C. What is the final pressure, in atmospheres, when the temperature is 39 ∘C, with no change in the volume or amount of gas?
Answer:
P₂ = 3.24atm
Explanation:
A football field is 120 yards by 53.333 yards. What is the area of the football field in acres if 1 acre=43560 ft?? Use correct
significant figures when answering this question.
Answer:
1.3223 acres
Explanation:
a football field's area is 360 feet (120 yards) x 160 feet (53.333 yards) = 57,600 sq. feet
if the area of an acre is 43,560 sq. feet, then a football field in acres = 57,600 sq. feet / 43,560 sq. feet = 1.3223 acres
we can verify our answer by doing the same calculation in sq. yards:
football field = 120 yards x 53.33 yards = 6,400 sq. yards
an acre is 4,840 sq. yards
football field in acres = 6,400 sq. yards / 4,840 sq. yards = 1.3223 acres
The area of the field is 1.3223 acres
From the question given above, the following data were obtained:
Dimension = 120 yard × 53.333 yard
Area =?The area of the field can be obtained as follow:
Area = Dimension
Area = 120 yard × 53.333 yard
Area = 6399.96 yard²Finally, we shall convert 6399.96 yard² to acre. This can be obtained as follow:
4840 yard² = 1 acre
Therefore,
6399.96 yard² = 6399.96 / 4840
6399.96 yard² = 1.3223 acresThus, the area of the field is 1.3223 acres
Learn more: https://brainly.com/question/1406215
Which of the following is a characteristic of the lanthanides?
O A. They are silvery metals that conduct electricity.
B. There are no known uses for the metals.
C. They are all radioactive.
D. They are used in making fireworks
Answer:
A
Explanation:
Lanthanides share the following common properties: Silvery-white metals that tarnish when exposed to air, forming their oxides. Relatively soft metals. Hardness increases somewhat with higher atomic number.
Answer:
APEX
Explanation:
A
A maple tree could be studied in many fields of science. What aspect of a maple tree might be studied in chemistry
Answer:
botany because a maple tree is a plant
Explanation:
The active ingredient in many commercial liquid bleaches is sodium hypochlorite. The bottle lists the percentage of sodium hypochlorite as 6.0%. If the density of commercial bleach is 1.084 g/mL, how many mL of 0.150 M sodium thiosulfate is required to reach the end point in a titration similar to the one performed in this experiment, if a student analyzed a 2.0 mL sample of bleach.
Answer:
23.3mL of 0.150M sodium thiosulfate
Explanation:
The net reaction of sodium hypochlorite (NaClO) with sodium thiosulfate (Na₂S₂O₃) is:
NaClO + 2 Na₂S₂O₃ + 2H₃O⁺ → NaCl + 3 H₂O + Na₂S₄O₆ + 2 Na⁺
2.0mL of the sample of bleach are:
2.0mL ₓ (1.084g / mL) ₓ (6 / 100) ₓ (1 mol / 74.44g) = 1.75x10⁻³ moles of NaClO
As 1 mole of NaClO reacts with 2 moles of thiosulfate:
1.75x10⁻³ moles of NaClO ₓ (2 mol Na₂S₂O₃ / 1 mol NaClO) =
3.50x10⁻³ moles of Na₂S₂O₃
If you have a 0.150M solution of thiosulfate, mL of this solution you need to reach the end point of the titration are:
3.50x10⁻³ moles of Na₂S₂O₃ ₓ (1L / 0.150mol) = 0.0233L =
23.3mL of 0.150M sodium thiosulfateBased on its location on the periodic table, how many electrons does nitrogen have in its outer energy level?
Answer:
its 5 got it right
Explain why the benzene molecule usually reacts with electrophiles
Answer:
Explanation:Because of the delocalised electrons exposed above and below the plane of the rest of the molecule, benzene is obviously going to be highly attractive to electrophiles - species which seek after electron rich areas in other molecules.
Answer:
Benzene has a pi electron system that is electron rich.
Electrophiles are molecules that are attracted to electron rich molecules as they are electron deficient in order to form a more stable complex.
Hence, as benzene is electron rich, electrophiles will be attracted to it.
The force that moves sediment in a landslide or mudflow is _.
Answer:
Erosion.
Explanation:
Erosion is the act of loose soil crumbling under itself and causes it to slide down a hill.
Answer:
erosion
Explanation:
Ashley notice that the mineral appear metallic under the light. What property was actually measuring?
Answer: The property is called Luster
Explanation:
Luster is a term used to describe the appearance of light from the surface of the mineral when it reflects light. The two types of classification of Luster is Mettalic or Non Mettalic.
some examples of minerals with mettalic lustre are --- Galena, graphite, Gold, Silver, Copper etc
Some examples of minerals with non mettalic lustre are--- Barite, Serpentine, Fluorite etc.
Answer:
Lustrous property
Explanation:
Materials like metals that have lustre usually glow or display sheen when light comes in contact with the surface of the material.
It is derived from the Latin word "lux" meaning "light", which is indicative of radiance or gloss.
Lustre is a common property of metals, including sonourousity, malleability and ductility amongst others.
1-Bromopropane is treated with each of the following reagents. Draw the major substitution product if the reaction proceeds in good yield. If no reaction is expected or yields will be poor, draw the starting material in the box. If a charged product is formed, be sure to draw the counterion.
a. with H_2 O
b. with H_2 SO_4
c. with 1 equiv of KOH
d. with Csl
e. with NaCN
f. with HCl
g. with (CH_3)_2 S
h. with 1 equiv of NH_3
j. with CI_2
k. with KF
Answer:
Explanation:
If we look at the structure of 1-Bromopropane; we will see that it is a derivative of alkane family by the the substitution of an alkyl group. The position of the Bromine in the propane is 1, making 1-Bromopropane a primary alkyl-halide.
Primary alkyl - halide undergo SN2 mechanism. This nucleophilic reaction needs to be a strong alkyl halide , such as 1-Bromopropane used otherwise it will result to a reactive mechanism if a weak electrophile is used.
However, the critical and the main objective here is to Draw the major substitution product if the reaction proceeds in good yield. If no reaction is expected or yields will be poor, draw the starting material in the box. If a charged product is formed, be sure to draw the counterion.
The attached diagrams portraying this notions is shown in the attached file below.
Why we need blood cholesterol?
Answer:
We need blood cholesterol because our body uses it to build your structure of cell membranes, make hormones like oestrogen, and testosterone, and to help your metabolism work well.
Answer:
our cells need some cholesterol but too much cuz it can cause problems. HDL carries cholesterol to your liver, where it can be removed from the body.so it helps protect your heart from atherosclerosis
Explanation:
A balloon is cooled by removing 0.784 kJ of heat. It shrinks on cooling, and the atmosphere does 655 J of work on the balloon. Calculate the change in internal energy, ∆E, of the system.
Answer:
The correct answer is -0.129 kJ
Explanation:
In the given case, the cooling of the balloon is done by withdrawing 0.784 J of heat, and the work done by the atmosphere on the balloon is 655 J. First, there is a need to transform kJ into J, 1 kJ = 1000 J. So, 0.784 kJ would be 784 J.
The ΔE or the change in the internal energy can be calculated by using the formula, ΔE = q + w ----- (1).
In the given case, q refers to the heat moved out of the system, that is, the value of q would be less than 0 or will be a negative quantity. Therefore, the heat moved out of the system will be -784 J. On the other hand, as the work or w is done on the system, therefore, the value of w would be more than 0 or will be a positive quantity. Thus, the value of w will be +655 J.
Now putting the values in the equation (1) we get,
ΔE = -784 J + 655 J
ΔE = -129 J or -0.129 kJ
As the change in internal energy comes out to be a negative value, therefore, the process is considered exothermic.
The number of cubic centimeters (cm) in 20.6 mL is
A) 0.0206 cm
B) 2.06 cm
I
C) 20.6 cm
D) none of these
Answer:
c
Explanation:
1 [tex]cm^{3}[/tex] = 1 mL
20,6 mL = 20,6 [tex]cm^{3}[/tex]
Answer:
C-20.6 cm^3
Explanation:
Cubic centimeters directly correspond to mL. Thus the answer would be the same as the mL
Addition of an excess of lead (II) nitrate to a 50.0mL solution of magnesium chloride caused a formation of 7.35g of lead (II) chloride precipitate. What was the molar concentration of chloride ions in the solution (in mol/L)?
Answer:
[Cl⁻] = 0.016M
Explanation:
First of all, we determine the reaction:
Pb(NO₃)₂ (aq) + MgCl₂ (aq) → PbCl₂ (s) ↓ + Mg(NO₃)₂(aq)
This is a solubility equilibrium, where you have a precipitate formed, lead(II) chloride. This salt can be dissociated as:
PbCl₂(s) ⇄ Pb²⁺ (aq) + 2Cl⁻ (aq) Kps
Initial x
React s
Eq x - s s 2s
As this is an equilibrium, the Kps works as the constant (Solubility product):
Kps = s . (2s)²
Kps = 4s³ = 1.7ₓ10⁻⁵
4s³ = 1.7ₓ10⁻⁵
s = ∛(1.7ₓ10⁻⁵ . 1/4)
s = 0.016 M
True or False: reactions in which the oxidation state of an element decreases are reduction processes
Answer:
False; An oxidation-reduction is any chemical process that involves any chemical process in which elements undergo changes in oxidation number. hope that helps love!
HBrO (aq) + H2O (l) ⇋ H3O+ (aq) + BrO- (aq)
If the value of Kc for this process is 5.2 x 10-5, there is no H3O+ or BrO- initially present, and the initial [HBrO] = 0.749 M, what will be the concentration of BrO- at equilibrium?
HINT: you should not use the quadratic formula for this problem.
7.67 x 10-3 M
9.01 x 10-3 M
5.17 x 10-3 M
4.29 x 10-3 M
6.24 x 10-3 M
Answer:
6.24 x 10-3 M
Explanation:
Hello,
In this case, for the given dissociation, we have the following equilibrium expression in terms of the law of mass action:
[tex]Ka=\frac{[H_3O^+][BrO^-]}{[HBrO]}[/tex]
Of course, water is excluded as it is liquid and the concentration of aqueous species should be considered only. In such a way, in terms of the change [tex]x[/tex], we rewrite the expression considering an ICE table and the initial concentration of HBrO that is 0.749 M:
[tex]5.2x10^{-5}=\frac{x*x}{0.749-x}[/tex]
Thus, we obtain a quadratic equation whose solution is:
[tex]x_1=-0.00627M\\x_2=0.00624M[/tex]
Clearly, the solution is 0.00624 M as no negative concentrations are allowed, so the concentration of BrO⁻ is 6.24 x 10-3 M.
Best regards.
Answer:
6.24×10¯³ M
Explanation:
Step 1:
The equation for the reaction is given below:
HBrO (aq) + H2O (l) ⇋ H3O+ (aq) + BrO- (aq)
Step 2:
The following data were obtained from the question:
Equilibrium constant, Kc = 5.2x10^-5
Concentration of HBrO, [HBrO] = 0.749 M
Concentration of BrO-, [BrO-] =?
Step 3:
Determination of the concentration of
BrO-.
We can obtain the concentration of BrO- as follow:
Initial concentration:
[HBrO] = 0.749 M
[H3O+] = 0
[BrO-] = 0
During reaction:
[HBrO] = - y
[H3O+] = +y
[BrO-] = +y
After reaction:
[HBrO] = 0.749 - y
[H3O+] = y
[BrO-] = y
Applying the equation constant equation:
Kc = [H3O+] [BrO-] / [HBrO]
5.2x10^-5 = y × y / 0.749
5.2x10^-5 = y² / 0.749
Cross multiply
y² = 5.2x10^-5 x 0.749
Take the square root of both side
y = √(5.2x10^-5 x 0.749)
y = 6.24×10¯³ M
[BrO-] = y = 6.24×10¯³ M
Therefore, the the concentration of BrO- at equilibrium is 6.24×10¯³ M
Identify which subatomic particles match each of these descriptions. One of the descriptions describes two particles. Make sure to include both particles it describes.
Description Particle(s)
have a relative charge of +1
have a relative charge of −1
have no charge
located in the nucleus of an atom
have a much lower mass than the other two types of particles
Explanation:
First off, it's important to know that the three subatomic particles we have are the proton, neutron and electron.
have a relative charge of +1 : This is the proton. It is the postive subatomic particle present in an atom.
have a relative charge of -1 : This is the electron. It is the negative subatomic particle present in an atom.
have no charge : This is the neutron. It is the neutral subatomic particle present in an atom.
located in the nucleus of an atom : Twoo subatomic particles are located in the nucleus, the neutron and proton.
have a much lower mass than the other two types of particles: This is the electron. The proton and neutron are almost similar in mass. The electron is abut 1 / 1840 times the mass of the proton.
Draw a Lewis structure for each covalent molecule. a. CH3F b. N2H4
Answer:
See attached picture.
Explanation:
Hello,
In this case, given the compounds we notice:
a. Since carbon has four valence electrons (group IVA), it has three hydrogen atoms around it as well as a fluorine atom which has seven valence electrons (group VIIA). Moreover, we notice both carbon and fluorine attaining the octet.
b. In this case, two nitrogen atoms which have five valence electrons each (groupVA) are bonded via a single bond and two hydrogen atoms are bonded to each nitrogen atom in order to attain the octet for nitrogen only.
Thus, structures are given on the attached picture.
Regards.
Lewis structure for each covalent molecule CH₃F and N₂H₄ are attached to the image below.
a. CH₃F:
Carbon (C) has 4 valence electrons, Hydrogen (H) has 1 valence electron, and Fluorine (F) has 7 valence electrons.
The total number of valence electrons in CH3F can be calculated as follows:
1 carbon atom (C) × 4 valence electrons = 4 valence electrons
3 hydrogen atoms (H) × 1 valence electron = 3 valence electrons
1 fluorine atom (F) × 7 valence electrons = 7 valence electrons
Total valence electrons = 4 + 3 + 7 = 14
b. N₂H₄:
Nitrogen (N) has 5 valence electrons, and Hydrogen (H) has 1 valence electron.
The total number of valence electrons in N2H4 can be calculated as follows:
2 nitrogen atoms (N) × 5 valence electrons = 10 valence electrons
4 hydrogen atoms (H) × 1 valence electron = 4 valence electrons
Total valence electrons = 10 + 4 = 14
To learn more about the Lewis structure, follow the link:
https://brainly.com/question/29603042
#SPJ6
Al2O3 would be typed in as Al2O3 Al2(SO4)3 would be typed in as Al2(SO4)3.
Required:
a. Write the formula for calciumnitride.
b. Write the formula for magnesium phosphide
c. Write the formula for rubidium chromate
d. Write the formula for aluminum nitrate
e. Write the formula for ammonium arsenide
f. Write the formula for nickel(II) nitrite
g. Write the formula for copper(I) sulfate
h. Write the formula for iron(III) nitrate
i. Write the formula for manganese(II) nitride
Answer:
Explanation:
Hello,
We are required to write the chemical formula of the following compounds
1. Calcium nitride = Ca₃N₂
2. Magnesium Phosphide = Mg₃P₂
3. Rubidium Chromate = Rb₂CrO₄
4. Aluminium nitrate = Al(NO₃)₃
5. Ammonium Arsenide = (NH₄)₃As
6. Nickel(ii) nitrite = Ni(NO₂)₂
7. Copper(i)sulfate = Cu₂SO₄
8. Iron(iii)nitrate = Fe(NO₃)₃
9. Manganese(ii)nitrate = Mn(NO₃)₂
The left hand side are the common names when the right hand side are the chemical formula.
How many grams of silver sulfide are formed when 0.280 g of hydrogen sulfide reacts with excess silver and oxygen?
Answer:
[tex]2.03~g~Ag_2S[/tex]
Explanation:
For this question we have to start with the reaction:
[tex]Ag~+~H_2S~+~O_2~->~Ag_2S~+~H_2O[/tex]
Now, we can balance the reaction, so:
[tex]4Ag~+~2H_2S~+~O_2~->~2Ag_2S~+~2H_2O[/tex]
With this in mind, we have to start with the amount of [tex]H_2S[/tex]. The first step is to convert from grams to moles. For this, we need to find the molar mass of [tex]H_2S[/tex]. If we check the periodic table we will find the atomic masses for Ag and H; H: 1 g/mol and A: 32 g/mol, so:
(1*2)+ (32*1) = 34 g/mol.
Now we can calculate the moles of [tex]H_2S[/tex]:
[tex]0.280~g~H_2S\frac{34~g~H_2S}{1~mol~H_2S}=0.0082~mol~H_2S[/tex]
With the moles of [tex]H_2S[/tex] we can calculate the moles of [tex]Ag_2S[/tex] if we check the molar ratio in the balanced equation, [tex]2~mol~H_2S=2~mol_Ag_2S[/tex], so:
[tex]0.0082~mol~H_2S\frac{2~mol_Ag_2S}{2~mol~H_2S}=0.0082~mol~H_2S[/tex]
With the molar mass of [tex]Ag_2S[/tex] we can convert from moles to grams (Ag: 107.86 g/mol, S: 32 g/mol), so:
(107.86*1)+(32*2)=247.80 g/mol
[tex]0.0082~mol~H_2S\frac{247.8~g~Ag_2S}{1~mol~H_2S}=2.03~g~Ag_2S[/tex]
I hope it helps!
Explain why airborne and water-borne chemicals are both local and global issues.
b) How many kilograms of carbon dioxide are formed when 24.42 g of iron is
produced?
Answer:
0.0289 kg of CO2 will be formed
Explanation:
Step 1: Data given
Mass of iron produced = 24.42 grams
Atomic mass iron = 55.845 g/mol
Molar mass CO2 = 44.01 g/mol
Step 2: The balanced equation
Fe2O3 + 3CO → 2Fe + 3CO2
Step 3: Calculate moles iron
Moles iron = mass iron / molar mass iron
Moles iron = 24.42 grams / 55.845 g/mol
Moles iron = 0.437 moles
Step 4: Calculate moles CO2
For 1 mol Fe2O3 we need 3 moles CO to produce 2 moles Fe and 3 moles CO2
For 0.437 moles Fe we'll have 3/2 * 0.437 = 0.6555 moles CO2
Step 5: Calculate mass CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 0.6555 moles * 44.01 g/mol
Mass CO2 = 28.85 grams = 0.0289 kg
0.0289 kg of CO2 will be formed
Erbium (Er) is element 68 on the periodic table. A sample contains 5.04×1023 atoms of Er. Calculate the amount of Er.
Answer:
139.98 g to nearest hundredth.
Explanation:
Using Avogadro's Number:
One mole (167.26 g) of Erbium equates to 6.022141 * 10^23 atoms.
So 5.04 * 10^23 = 167.26 * 5.04/6.022141
= 139,98 g.
Sodium metal and water react to form hydrogen and sodium hydroxide. If 11.96 g of sodium react with water to form 0.52 g of hydrogen and 20.80 g of sodium hydroxide, what mass of water was involved in the reaction
Answer:
9.36g of H2O.
Explanation:
We'll begin by writing the balanced equation for the reaction.
2Na + 2H2O —> 2NaOH + H2
Next, we shall determine the mass of Na and H2O that reacted from the balanced equation.
This is illustrated below:
Molar mass of Na = 23g/mol
Mass of Na from the balanced equation = 2 x 23 = 46g
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mass of H2O from the balanced equation = 2 x 18 = 36g
From the balanced equation above,
46g of Na reacted with 36g of H2O.
Now, we can determine the mass of H2O involved in reaction as follow:
From the balanced equation above,
46g of Na reacted with 36g of H2O.
Therefore, 11.96g of Na will react with = (11.96 x 36)/46 = 9.36g of H2O.
Therefore, 9.36g of H2O were used for the reaction.
7. Which molecular solid would have the lowest boiling point?
a. One that has hydrogen bonding
b. One made of molar molecules
c. One with dipole-dipole attractions
d. One with induced dipole attractions
Answer:
The molecular solids would have the lowest boiling point because of WEAK INTERMOLECULAR FORCES.
Explanation:
Answer: One with induced dipole attractions
the amount of order in an isolated system cannot increase; it may only stay the same or decrease. This expresses which of the following?
Conservation of mass
The First Law of Thermodynamics
The second Law of Thermodynamics
Kinetic Theory
The definition of work
the definition of heat
Answer:
Second law of thermodynamics.
Explanation:
Second law of thermodynamics states the entropy or order in an isolated system always increases. The isolated system evolve spontaneously toward thermal thermal equilibrium.
For example if a room is untidy and dirty,it will become messy over time and disorder. So when the room is cleaned, there won't be disorderliness and entropy will decrease.
