Answer:
It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.
The atomic numbers of some elements such as Protonium were just guessed.
A student is making a solution of sodium carbonate (Na2CO3) they mix 0.79 grams of sodium carbonate into 50.0 mL of water. What is the molarity of the sodium carbonate solution?
A 0.15 M Na2CO3
B 1.5 x 10^-4 M Na2CO3
C 6.7 M Na2CO3
D 15.8 M NaCO3
Answer:
[Na₂CO₃] = 0.15 M
Explanation:
Molarity is a type of concentration.
It is useful for solutions, to say how many moles of solute are contained in 1L of solution.
We can also say, that molarity are the mmoles of solute in 1 mL of solution.
In this case, our solute is the Na₂CO₃.
We convert mass to moles: 0.79 g . 1 mol / 106g = 7.45×10⁻³ moles
We convert moles to mmoles: 7.45×10⁻³ mol . 1000 mmol / 1mol = 7.45 mmol
M = mmol / mL
M = 7.45 mmol / 50 mL = 0.15 M
Option A is the right answer.
g When aqueous solutions of and are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M is mixed with an excess of an aqueous solution of .
The question is incomplete, the complete question is:
When aqueous solutions of NaCl and [tex]Pb(NO_3)_2[/tex] are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M NaCl is mixed with an excess of an aqueous solution of
Answer: The mass of lead chloride produced is 1.96 g
Explanation:
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}[/tex] .....(1)
Given values:
Molarity of NaCl = 0.1000 M
Volume of the solution = 140.7 mL
Putting values in equation 1, we get:
[tex]0.1000=\frac{\text{Moles of NaCl}\times 1000}{140.7}\\\\\text{Moles of NaCl}=\frac{0.1000\times 140.7}{1000}=0.01407mol[/tex]
The chemical equation for the reaction of NaCl and lead nitrate follows:
[tex]Pb(NO_3)_2(aq)+2NaCl(aq)\rightarrow PbCl_2(s)+2NaNO_3(aq)[/tex]
By the stoichiometry of the reaction:
If 2 moles of NaCl produces 1 mole of lead chloride
So, 0.01407 moles of NaCl will produce = [tex]\frac{1}{2}\times 0.01407=0.007035mol[/tex] of lead chloride
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(2)
Molar mass of lead chloride = 278.1 g/mol
Plugging values in equation 2:
[tex]\text{Mass of lead chloride}=(0.007035mol\times 278.1g/mol)=1.96g[/tex]
Hence, the mass of lead chloride produced is 1.96 g
A liquid solvent is added to a flask containing an insoluble solid. The total volume of the solid and liquid together is 80.0 mL. The liquid solvent has a mass of 21.0 g and a density of 0.865 g/mL. Determine the mass of the solid given its density is 2.00 g/mL.
Answer:
111.44 g
Explanation:
We'll begin by calculating the volume of the solvent. This can be obtained as follow:
Mass of solvent = 21 g
Density of solvent = 0.865 g/mL.
Volume of solvent =?
Density = mass /volume
0.865 = 21 /volume of solvent
Cross multiply
0.865 × volume of solvent = 21
Divide both side by 0.865
Volume of solvent = 21 / 0.865
Volume of solvent = 24.28 mL
Next, we shall determine the volume of the solid. This can be obtained as follow:
Volume of solvent + solid = 80.0 mL.
Volume of solvent = 24.28 mL
Volume of solid =?
Volume of solid = (Volume of solvent + solid) – (Volume of solvent)
Volume of solid = 80 – 24.28
Volume of solid = 55.72 mL
Finally, we shall determine the mass of the solid. This can be obtained as follow:
Density of solid = 2.00 g/mL.
Volume of solid = 55.72 mL
Mass of solid =.?
Density = mass / volume
2 = mass of solid / 55.72
Cross multiply
Mass of solid = 2 × 55.72
Mass of solid = 111.44 g
Therefore, the mass of the solid is 111.44 g
You are in the laboratory and are performing a nucleophilic substitution reaction. You do not know the structure of the starting material or product but are asked to determine whether the reaction proceeds via an SN1 or SN2 mechanism. Using your knowledge of general chemistry and your experience of organic chemistry so far, devise a method for solving the problem as to which mechanism is in operation in your reaction.
Answer:
Let’s break down all the steps in the following SN1 reaction looking at the energy diagram: Step Breaking the C – LG bond. In this rate-determining step, a carbocation intermediateis formed: Step A nucleophilic attack.The carbocation is highly electron-deficient and the nucleophile attacks as a Lewis base usin…
Image
Explanation:
Distinguish between
real and virtuaI image
Answer:
(Basic )
Real
These are formed in the front side of the mirror.
Virtual
These are assumed to be formed at the backside of the mirror.
Type of lens used
Converging(real)
Diverging(virtual)
Image reception
Image can be appeared on a screen.(Real)
Image appears to be on the mirror or lens itself.
Interaction of light rays Actual Imaginary(Virtual)
Appearance of image
Inverted(Real)
Erect(Virtual)
Formed by
Concave mirror and convex lens.(Real)
Plane, convex mirror and concave lens.(Virtual)
Example
Image on the theater screen.(Real)
Reflection of any object or body on plane mirror.(Virtual)
_____ properties include melting point, boiling point, strength, and malleability
Answer:
physical propertiesphysical properties include melting point, boiling point, strength, and malleability.
Explanation:
hope it may help youAnswer:
Metal properties.
Explanation:
metal has its fix point to melt and boil expect mercury because it doesn't have its own fix point of melting or boiling, strength- if metal is heated then it can be strength and we can give it shape by heating
Calculate the volume of 0.320-M NaOH solution needed to completely neutralize 74.0 mL of a 0.230-M solution of the monoprotic acid HBr. mL NaOH.
Answer:
53.2 mL
Explanation:
As this problem deals with the neutralization of a strong monoprotic acid and a strong base, we can solve it by using the following formula:
Ca * Va = Cb * VbWhere in this case:
Ca = 0.230 MVa = 74.0 mLCb = 0.320 MVb = ?We input the data:
0.230 M * 74.0 mL = 0.320 M * VbAnd solve for Vb:
Vb = 53.2 mL13. What does the Law of Conservation of Mass state?
1 pc
8. Some chemicals, most often inorganic salts, in the laboratory have the nasty tendency to absorb water from the
atmosphere. This property is called hygroscopicity. Anhydrous (water-free) Cupric Perchlorate [Cu(C104)2] weighs
262.447g/mol, but after sitting on out on the benchtop absorbs water from the air and now weighs 370.540g/mol. How
many water molecules did our Cupric Perchlorate absorb?
I need help please ASAP
Answer:
the name for NO is nitrogen monoxide
Define pure substance. How is it classified on the basid of chemical properties?
Answer:
if it is pure, the substances is either an element or a compound. if a substance is not chemically pure, it is either a heterogeneous mixture or a homogeneous mixture. if its composition is uniform throughout, it is a homogeneous.
A central idea in modern quantum mechanics is:
(4 Points)
A wave character exhibited by all particles.
The acceleration of charged particles moving around a nucleus.
The opportunity to locate the position of an electron exactaly.
The continuous range of energies that electrons can have.
Answer:
A wave character exhibited by all particles
Explanation:
The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.
The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.
These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.
Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.
Find the volume of 6.45 moles of gas present at a temperature of 27.0oC and a pressure of 675 torr.
Answer: The volume of the gas is 178.76 L
Explanation:
The ideal gas equation is given as:
.......(1)
where
P = pressure of the gas = 675 torr
V = volume of gas = ?
n = number of moles of gas = 6.45 moles
R = Gas constant = 62.36 L.torr/mol.K
T = temperature of the gas = [tex]27^oC=[27+273]K=300K[/tex]
Putting values in equation 1, we get:
[tex]675torr\times V=6.45mol\times 62.36L.torr/mol.K\times 300K\\\\V=\frac{6.45\times 62.36\times 300}{675}=178.76 L[/tex]
Hence, the volume of the gas is 178.76 L
How many molecules of carbon dioxide would be formed if 6.75 g of propane is burned in the following reaction?
dont mind me here for the points
g Using Newman projections, draw the most stable conformation for each of the following compounds. (a) 3-methyl pentane, viewed along the C2-C3 bond (b) 3,3-dimethyl hexane, viewed along the C3-C4 bond
Answer:
Using Newman projections, draw the most stable conformation for each of the following compounds.
(a) 3-methyl pentane, viewed along with the C2-C3 bond.
(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.
Explanation:
(a) The structure of 3-methyl pentane is shown below:
In Newman projection, the most stable conformation is staggard conformation.
In staggard conformation, the torsional strain is very less compared to eclipsed conformation.
(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.
A chemist requires a large amount of 3-bromo-3-methyl-1-cyclohexene as starting material for a synthesis and decides to carry out the following NBS allylic bromination reaction in the presence of UV light. Draw the structures of all of the observed products.
Answer:
Explanation:
Bromination of allylic compounds occurs when hydrogen atoms from neighboring double bonds are replaced. As a result, there are four (4) potential bromination products, as seen in the figure below.
NBS, also known as N-Bromo succinimide, is employed as a replacement for Br2 in certain instances. The benefit of NBS is that it produces a reduced level concentration for Br2, which means that bromination of the double bond isn't competitive. As soon as Br2 has been produced, the reaction continues in the same way as the remaining free-radical halogenation reactions.
Identify the number of core and valence electrons for each atom. XeXe : core electronscore electrons XeXe : valence electronsvalence electrons CaCa : core electronscore electrons CaCa : valence electronsvalence electrons II : core electronscore electrons II : valence electrons
Answer:
See explanation
Explanation:
In writing the electron configuration of atoms, the core electrons are those electrons that occur in the inner shells. They do not participate in chemical reaction.
The valence electrons are those electrons that occur on the outermost shell of an atom and does participate in chemical reaction.
For Xe, the core electrons are; 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10 while the valence electrons are; 5s25p6
For Ca, the core electrons are; 1s2 2s2 2p6 3s2 3p6 while the valence electrons are 4s2.
Hence, there are 18 core electrons and 2 valence electrons for Ca and 46 core electrons for Xe and 8 valence electrons
Compound X has the formula C8H14.
X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethylcyclohexane. Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?
Answer:
Compound X has the formula C8H14.
X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethyl cyclohexane. Treatment of X with ozone followed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?
Explanation:
The degree of unsaturation in the given molecule C8H14 is:
DU=(Cn+1)-Hn/2-Xn/2+Nn/2
where,
Cn=number of carbon atoms
Hn=number of hydrogen atoms
Xn=number of halogen atoms
Nn=number of nitrogen atoms
C8H14:
DU=(8+1)-14/2
=>DU=9-7 =2
Hence, the given molecule will have either two double bonds or one double bond and one ring or two rings.
X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethylcyclohexane.
This indicates that the molecule X has one double bond and one ring that is cyclohexane ring.
Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O).
So, the molecule has a ring and double bond CH2.
Based on the given data the structure of compound X is shown below:
The reaction sequence is shown below:
How much water, in grams, can be made from
2.44 × 10^24 hydrogen molecules?
Answer in units of g.
Answer:
[tex]m_{H_2O}=73.0gH_2O[/tex]
Explanation:
Hello there!
In this case, since the formation of water from hydrogen and oxygen is:
[tex]2H_2+O_2\rightarrow 2H_2O[/tex]
Whereas we find a 2:2 mole ratio of hydrogen to water. In such a way, by using the Avogadro's number, the aforementioned mole ratio and the molar mass of water (18.02 g/mol), we obtain the following grams of water product:
[tex]m_{H_2O}=2.44x10^{24}molec*\frac{1molH_2}{6.022x10^{23}molec}*\frac{2molH_2O}{2molH_2}*\frac{18.02gH_2O}{1molH_2O}\\\\ m_{H_2O}=73.0gH_2O[/tex]
Regards!
The neutralization of any strong acid and strong base produces mostly
Explanation:
Neutralization is the reaction between an acid and a base, producing a salt and a neutralized base. A strong acid yields a weak conjugate base (A–), so a strong acid is also described as an acid whose conjugate base is a much weaker base than water.
HELPPPPPPPPPPPPMEEEEEEEEEE
Answer:
25%
Explanation:
Cystic fibrosis is a recessive allele, meaning that the child must be aa to suffer the symptoms. Only 1/4 of the paired alleles is aa, so the probability of getting cystic fibrosis would be 25%.
How many grams of carbon atoms are present in a sample of C3H8 if there are 4.70 moles of hydrogen atoms in the sample
Answer:
21.12 grams
Explanation:
Using the given number of hydrogen moles, we calculate the number of carbon atoms, keeping in mind that there are 3 carbon moles per hydrogen mol:
4.70 mol H * [tex]\frac{3molC}{8molH}[/tex] = 1.76 mol C
Finally we convert 1.76 moles of carbon into grams, using its molar mass:
1.76 mol * 12 g/mol = 21.12 g
Determine the mass in grams of hydrogen gas produced if 40.08 g of calcium react with excess aqueous hydrogen phosphate.
Answer:
[tex]2.02gH_2[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to to calculate the mass of hydrogen gas by firstly setting up the undergoing chemical reaction:
[tex]2H_3PO_4+3Ca\rightarrow Ca_3(PO_4)_2+3H_2[/tex]
Thus, we apply the following stoichiometric setup, whereas the atomic mass of calcium is 40.08 g/mol, that of hydrogen is 2.02 g/mol and the mole ratio of these two substances is 3:3:
[tex]40.08gCa*\frac{1molCa}{40.08gCa}*\frac{3molH_2}{3molCa}*\frac{2.02gH_2}{1molH_2} \\\\=2.02gH_2[/tex]
Regards!
Identify whether longhand notation or noble-gas notation was used in each case below.
Iron (Fe): [Ar]4s23d6
Answer: The given electronic configuration is long hand notation.
Explanation:
Long-hand notation of representing electronic configuration is defined as the arrangement of total number of electrons that are present in an element.
Noble-gas notation of representing electronic configuration is defined as the arrangement of valence electrons in the element. The core electrons are represented as the previous noble gas of the element that is considered.
The given electronic configuration of potassium (K):
The above configuration has all the electrons that are contained in the nucleus of an element. Thus, this configuration is a long-hand notation.
What is the Name of molecule and smiles strings ?
Explanation:
Aromatic nitrogen bonded to hydrogen, as found in pyrrole must be represented as [nH] ; thus imidazole is written in SMILES notation as n1c[nH]cc1 . When aromatic atoms are singly bonded to each other, such as in biphenyl, a single bond must be shown explicitly: c1ccccc1-c2ccccc2 .
what is the answer to this?
Answer:
5-Ethyl3-Methyloctane
Explanation:
Step in the naming of organic compound
Step 1: Take the longest continous carbon chain as the root hydrocarbon and name it according to the number of carbon atoms it contains, adding appropriate suffix to indicate the principal substituent group
Step 2: Number the carbon atoms in the root hydrocarbons from the end which give the lowest number to the suffix, and then the prefix
Step 3: Indicate other substituents by prefixes proceed by numbers to show their positions on the carbon chain
Applying the step above,
The longest carbon chain is 8, and the fuctional group is the single chain (alkane),
5-Ethyl3-Methyl,octane
how many joules of heat are required to heat 100.0g of room temperature water to the boiling point
Answer:
To convert 100.0 g of water at 20.0 °C to steam at 100.0 °C requires 259.5 kJ of energy. Let me know if this helped?
Gizmo Warm-up Like an unpopped kernel in the microwave, a radioactive atom can change at any time. Radioactive atoms change by emitting radiation in the form of tiny particles and/or energy. This process, called decay, causes the radioactive atom to change into a stable daughter atom. The Half-life Gizmo allows you to observe and measure the decay of a radioactive substance. Be sure the sound is turned on and click Play
Answer:
Fission reaction occurs.
Explanation:
When a radioactive atom undergoes a nuclear decay event, spontaneous fission reaction occurs, the decaying nucleus undergoes a transformation in the change in the number of protons in the nucleus. The fission process produces gamma photons, and releases a very large amount of energy. After the radiation stops, a stable element is obtained whereas the energy is released in the surrounding.
What is the noble gas electron configuration of bismuth (Bi)?
Answer:
The chemical symbol for Bismuth is Bi. Electron Configuration and Oxidation States of Bismuth. Electron configuration of Bismuth is [Hg] 6p3. Possible oxidation states are +3,5.
I'M IN NEED OF HELP!! 40 POINTS!!! This is the last question on my assignment and i can't seem to get past it. Please help!!
How many grams of KCI are produced when 12.5 moles of KOH completely react with excess of FeCI3?
Thank you to whoever answers!!!!
1 mole KOH give 1 mole KCl
so 12.5 will give 12.5 mole of KCl
we know that 1 mole of kcl is equal to 74 grams
so 12.5 mole have
12.5 × 74= 926 grams