Answer:
there's no image can't help without it sorry
The reason for the dramatic decline in the number of measles cases from the 1960s to 2010 in the United States was because the vaccine
Answer:
It was because the vaccine generated actively acquired immunity, that is, inoculation of a portion of the measles virus so that the body forms the antibodies for a second contact and thus can destroy it without triggering the pathology.
Explanation:
Vaccines are methods of active acquired immunity since the antibody is not passively inoculated, it is manufactured by the body with a physiological process once part of the virus is inoculated.
The measles virus most of all affected the lives of infants or newborn children with severe rashes and high fevers that led to death.
Question 1
1 pts
2B+6HCI --
| --> 2BCl3 + 3H2
How many moles of boron chloride will be produced if you start with 8.752 moles of HCI
(hydrochloric acid)? (Round to 3 sig figs. Enter the number only do not include units.)
Answer:
2.92 mol
Explanation:
Step 1: Write the balanced equation
2 B(s) + 6 HCI(aq) ⇒ 2 BCl₃(aq) + 3 H₂(g)
Step 2: Establish the appropriate molar ratio
The molar ratio of hydrochloric acid to boron chloride is 6:2.
Step 3: Calculate the moles of boron chloride produced from 8.752 moles of hydrochloric acid
[tex]8.752molHCl \times \frac{2molBCl_3}{6molHCl} = 2.92molBCl_3[/tex]
What is the net ionic equation of the reaction of MgSO4 with Ba(NO3)2 ?
Answer:
Ba(+2)(aq) + SO4(-2)(aq) -----> BaSO4(s)
Explanation:
Take a look at the attachment below;
When 1-iodo-1-methylcyclohexane is treated with NaOCH2CH3 as the base, the more highly substituted alkene product predominates. When KOC(CH3)3 is used as the base, the less highly substituted alkene predominates. Give the structures of the two products and offer an explanation.
Answer:
See explanation
Explanation:
In this case, we have 2 types of reactions. [tex]CH_3CH_2ONa[/tex] is a strong base but only has 2 carbons therefore we will have less steric hindrance in this base. So, the base can remove hydrogens that are bonded on carbons 1 or 6, therefore, we will have a more substituted alkene (1-methylcyclohex-1-ene).
For the [tex]KOC(CH_3)_3[/tex] we have more steric hindrance. So, we can remove only the hydrogens from carbon 7 and we will produce a less substituted alkene (methylenecyclohexane).
See figure 1
I hope it helps!
A certain mass of carbon reacts with 9.53 g of oxygen to form carbon monoxide. ________ grams of oxygen would react with that same mass of carbon to form carbon dioxide, according to the law of multiple proportions.
Answer: 9.53 *2= 19.06
Explanation:
The law of multiple proportions states that if two elements combines to form more than one compound the ratio of masses of the second element which combines to the fixed mass of the first element will always be the ratios of the small whole numbers.
in case of carbon monoxide, mass of carbon will be the same of mass of oxygen.
But in case of carbon dioxide, if carbon is 9.53 units then oxygen will be twice as that of carbon.
CO2, so 9.53*2= 19.06 grams of oxygen will combine with 9.53 grams of carbon to form carbon dioxide.
Calculate ΔG (in kJ) for the following reaction at 1.0 atm for C2H6, 0.5 atm for O2, and 2.0 atm for CO2, and 25 oC: C2H6 (g) + O2 (g) ---> CO2 (g) + H2O (l) (unbalanced) ΔGfo C2H6 (g) = - 32.89 kJ/mol; ΔGfo CO2 (g) = - 394.4 kJ/mol; ΔGfo H2O (l) = - 237.13 kJ/mol
Answer:
Explanation:
Calculate ΔG (in kJ) for the following reaction at 1.0 atm for C2H6,
0.5 atm for O2, and
2.0 atm for CO2, and
25 oC:
C2H6 (g) + O2 (g) ---> CO2 (g) + H2O (l) (unbalanced)
ΔGfo C2H6 (g) = - 32.89 kJ/mol;
ΔGfo CO2 (g) = - 394.4 kJ/mol;
ΔGfo H2O (l) = - 237.13 kJ/mol
The balance equation of this reaction is
[tex]2C_2H_6 (g) + 7O_2 (g) ---> 4CO_2 (g) + 6H_2O (l)[/tex]
[tex]\Delta G_{rxn}=\sum G^o_f(product)-\sum G^o_f(reactant)[/tex]
[tex]=4G^o_f(CO_2)+6G^o_f(H_2O)-7G^o_f(O_2)-2G^o_f(C_2H_6)\\\\[/tex]
[tex][4(-394.4)+6(-237.13)-7(0)-2(-32.89)]kJ/mol\\\\=-1577.6-1422.78+65.78\\\\=-3000.38+65.78\\\\=-2934.6kJ/mol[/tex]
What is the coefficient for oxygen in the balanced equation? C 5H 12 + ? O2 → ? CO2 + ? H2O. 2 4 5 6 8
Answer:
8
Explanation:
When you balance the entire equation, you should get:
C5H12 + 8O2 ---> 5CO2 + 6H2O
What is the law of conservation and what happens when two substances at different temperatures come into contact.
Answer:
- Both energy and matter cannot be neither created nor destroyed.
- An equilibrium temperature will be reached.
Explanation:
Hello,
In this case, the law of conservation is applied to both matter and energy, and it states that both energy and matter cannot be neither created nor destroyed. Specifically, in chemical reactions, it states that in closed systems, the mass of the reactants equals the mass of the products even when the number of moles change. Moreover, for energy, if two substances at different temperatures come into contact, the hot one will cool down and the cold one will heat up until an equilibrium temperature so the energy lost by the hot one is gained by the cold one, which accounts for the transformation of energy.
Best regards.
How many moles of CO2 can be produced by the complete reaction of 1.0 g of lithium carbonate with excess hydrochloric acid (balanced chemical reaction is given below)? Li2CO3(s) + 2HCl(aq) --> 2LiCl(aq) + H2O(l) + CO2(g) Question 1 options: 1.7 g 1.1 g 0.60 040 g
Answer:Mass of CO2 = 0.60g
Explanation:
Given the chemical rection
Li2CO3(s) + 2HCl(aq) --> 2LiCl(aq) + H2O(l) + CO2(g
No of moles = mass / molar mass
molar mass Li2CO3 = Molecular mass calculation: 6.941 x 2 + 12.0107 + 15.9994 x 3 =
= 73.8909 g/mol
therefore Number of moles Li2CO3 = 1.0g / 73.89 g/mol
= 0.0135 moles Li2CO3
From our given Balanced equation, shows that
Li2CO3(s) + 2HCl(aq) --> 2LiCl(aq) + H2O(l) + CO2(g
1 mole Li2CO3 produces 1 mole CO2
therefore 0.0135 mol Li2CO3 will produce 0.0135 moles of CO2
Also
No of moles = mass / molar mass
Mass = No of moles x molar mass
molar mass of CO2=12.0107 + 15.9994 x 2=44.0095 g/mol
Mass of CO2= 0.0135 X 44.0095 g/mol =0.594≈0.60g
Enter your answer in the provided box. On a cool, rainy day, the barometric pressure is 739 mmHg. Calculate the barometric pressure in centimeters of water (cmH2O) (d of Hg = 13.5 g/mL; d of H2O = 1.00 g/mL).
Answer:
997.65cmH2O
Explanation:
Barometric pressure = 739 mmHg
density of Hg = 13.5 g/ml
density of water (H2O) = 1.00 g/ml
Calculate Barometric pressure in centimetres of water ( cmH20)
equate the barometric pressure of Hg and water
739 * 13.5 * 9.8 = x * 1 * 9.81
x ( barometric pressure of water in mmH2O ) = 739 *13.5 / 1 = 9976.5mmH2O
in cmH2O = 997.65cmH2O
Please what's the missing minor products? And kindly explain in your own words how they were formed. Thank you!
Answer:
it's a two step elimination reaction
Explanation:
it follows a carbocationic pathway. When carbocation is stable, the equation is favourable, that is, double bond is formed by expelling hydrogen atom.
Among three bases, X−, Y−, and Z−, the strongest one is Y−, and the weakest one is Z−. Rank their conjugate acids, HX, HY, and HZ, in order of decreasing strength. Rank the acids from strongest to weakest. To rank items as equivalent, overlap them.
Answer: HZ > HX > HY in order of decreasing strengths.
Explanation: Generally, the rule is that the stronger the acid, the weaker its conjugate base and vice versa; same rule applies for bases and their conjugate acids.
So the weakest base Z- would have the strongest conjugate acid. Consequently, the strongest base Y- would have the weakest conjugate acid.
I hope this was MORE helpful as this is the correct answer.
The ranking of the conjugate acids in order of decreasing strength (i.e from strongest to weakest) is; HZ < HX < HY
First we must know that the stronger a base is, the weaker is it's conjugate acid and the weaker a base is, the stronger is it's conjugate acid.
Therefore, the order of decreasing strength of the conjugate acid is; HZ < HX < HY
Read more:
https://brainly.com/question/23917439
Convert 150 K to degrees C.
Answer:
K = 150, C = - 123.15°
Explanation:
Kelvin = Celcius + 273.15 / 0 Kelvin = - 273.14 C
_____________________________________
Thus,
150 K = Celcius + 273.15,
150 - 273.15 = C,
C = -123.15 degrees
Solution, C = - 123.15°
Answer:
C=-123.15
Explanation:
This is easy
Carbon dioxide and water vapor are variable gases because _____.
Answer: their amounts vary throughout the atmosphere
Explanation:
There is very little that travels over the atmosphere
Vary=very little
Hope that helps
A solution of benzene in methanol has a transmittance of 93.0 % in a 1.00 cm cell at a wavelength of 254 nm. Only the benzene absorbs light at this wavelength, not the methanol. What will the solution's transmittance be if it is placed in a 10.00 cm long pathlength cell
Answer:
T = 48.39%
Explanation:
In this case we need to apply the Beer law which is the following:
A = CεL (1)
Where:
A: Absorbance of solution
C: Concentration of solution
ε: Molar Absortivity (Constant)
L: Length of the cell
Now according to the given data, we have transmittance of 93% or 0.93. We can calculate absorbance using the following expression:
A = -logT (2)
Applying this expression, let's calculate the Absorbance:
A = -log(0.93)
A = 0.03152
Now that we have the absorbance, let's calculate the concentration of the solution, using expression (1).
A = CεL
C = A / εL
Replacing:
C = 0.03152 / 1 *ε (3)
Now, we want to know the transmittance of the solution with a length of 10 cm. so:
A = CεL
Concentration and ε are constant, so:
A = (0.03152 / ε) * ε * 10
A = 0.3152
Now that we have the new absorbance, we can calculate the new transmittace:
T = 10^(-A)
T = 0.4839 ----> 48.39%
What is Key for the reaction 2503(9) = 2802(9) + O2(g)?
Answer:
Option C. Keq = [SO2]² [O2] /[SO3]²
Explanation:
The equilibrium constant keq for a reaction is simply the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient.
Now, let us determine the equilibrium constant for the reaction given in the question.
This is illustrated below:
2SO3(g) <==> 2SO2(g) + O2(g)
Reactant => SO3
Product => SO2, O2
Keq = concentration of products /concentration of reactants
Keq = [SO2]² [O2] /[SO3]²
what’s the SI unit of time ?
Answer:
The answer is A
Explanation:
AMMONIUM CARBONATE
5. How many grams of nitrogen (N) are in a mass of ammonium carbonate that contains
1.23x10^23 carbon atoms?
Answer:
Zero
Explanation:
Hello,
The question require us to calculate the mass of nitrogen present in aluminium carbonate.
This can easily be calculated using Avogadro's number as a constant with some minor calculations but however in this case, we can't because there's no single atom of nitrogen present in aluminium carbonate hence we can't calculate the mass of nitrogen present in it.
Chemical formula of aluminium carbonate = Al₂(CO₃)₃.
From the above chemical formula, we can see that there's no single atom of nitrogen present in the formula hence the mass of nitrogen present in aluminium carbonate that contains 1.23×10²³ carbon atoms is zero.
A solution that is 0.135 M is diluted to make 500.0 mL of a 0.0851 M solution. How many milliliters of the original solution were required? View Available Hint(s) A solution that is 0.135 M is diluted to make 500.0 mL of a 0.0851 M solution. How many milliliters of the original solution were required? 5.74 mL 0.315 mL 793 mL 315 mL
Answer:
315mL
Explanation:
Data obtained from the question include the following:
Molarity of stock solution (M1) = 0.135 M
Volume of stock solution needed (V1) =?
Molarity of diluted solution (M2) = 0.0851 M
Volume of diluted solution (V2) = 500mL
The volume of the stock solution needed can be obtain as follow:
M1V1 = M2V2
0.135 x V1 = 0.0851 x 500
Divide both side by 0.135
V1 = (0.0851 x 500) / 0.135
V1 = 315mL
Therefore, the volume of the stock solution needed is 315mL
need helpp asapp please
Answer:
B. None of these
Explanation:
Sulfur has less ionization energy than phosphorus because sulfur has a pair of electron in its 3p subshell that increases electron repulsion in sulfur and sulfur electrons can easily remove from its sub-level.
While, there are no electron pairs in 3p subshell of phosphorus, therefore it requires more energy to remove an electron from 3p subshell.
Hence, the reason is electron repulsion and the correct answer is B.
all compounds are neutral true or false
Answer:
Even all compounds are neutral.
Explanation:
Some of them exhibit polarity. Because of the difference in electron affinity of the constituent atoms, the shared electrons are pulled towards the atom with high affinity to electrons.
A solid is dissolved in a liquid, and over time a solid forms again. How can
you confirm the type of change that took place?
A. Testing the new solid to show that its properties are the same as
the starting solid would confirm that a physical change took
place.
B. The solid dissolving in a liquid is confirmation that a chemical
change took place.
C. The solid forming from the liquid is confirmation that a physical
change took place.
D. Showing that the total mass of the solid and liquid changed would
confirm that a chemical change took place.
When an automobile engine starts, the metal parts immediately begin to absorb heat released during the combustion of gasoline. How much heat will be absorbed by a 165 kg iron engine block as the temperature rises from 15.7°C to 95.7°C? (The specific heat of iron is 0.489 J/g·°C.)
Answer:
H = 4,034,250 J
Explanation:
Mass, m = 165kg = 165,000g (Converting to grams)
Initial temperature = 15.7°C
Final temperature = 95.7°C
Temperature change, ΔT = 95.7 - 15.7 = 50°C
Specific heat capacity, c = 0.489 J/g·°C
Heat = ?
All the parameters are related with the equation below;
H = m * c * ΔT
H = 165000 * 0.489 * 50
H = 4,034,250 J
What is an ion?
A. An atom that has lost or gained 1 or more electrons
O B. An atom that has lost or gained 1 or more neutrons
O C. An atom that has lost or gained 1 or more protons
D. An atom that differs in mass from another atom of the same
element
Answer:
An ion is an atom that has lost or gained one or more electrons.
Explanation:
Ions are positively or negatively charged atoms of elements. This is because they can give, take, or share electrons with other elements to encourage the formation of chemical bonds.
Protons are what decide the chemical identity of the element. So, for example, if an atom has 11 protons, we know that will be a Sodium (Na) atom. A loss or gain of protons completely changes the chemical identity of the element and it will then become another element.
Electrons are what give an atom a neutral electrical charge (if that atom has the number of protons and neutrons normally described for the element - otherwise, a discrepancy or gain in neutrons is referred to as an isotope and declares that ions have nothing to do with the mass of an element).
With this information, you can realize that neutrons and protons have nothing to do with ions and you can confirm that ions are atoms that have lost or gained one or more electrons.
A solution is prepared by mixing 5.00 mL of 0.100 M HCl and 2.00 mL of 0.200 M NaCl. What is the molarity of chloride ion in this solution?
Answer:
0.129 M
Explanation:
0.100 M HCl = 0.100 mol/L solution HCl
5.00 mL = 0.00500 L solution HCl
0.100 mol/L HCl * 0.00500 L = 0.000500 mol HCl
HCl ------> H+ + Cl-
1 mol 1 mol
0.000500 mol 0.000500 mol
0.200 M NaCl = 0.200 mol/L solution NaCl
2.00 mL = 0.00200 L solution NaCl
0.200 mol/L NaCl*0.00200 L = 0.000400 mol NaCl
NaCl ------> Na+ + Cl-
1 mol 1 mol
0.000400 mol 0.000400 mol
Chloride ion altogether (0.000500 mol + 0.000400 mol) =0.000900 mol
Solution altogether (0.00500 L+0.00200 L) = 0.00700L
Molarity (Cl-)= solute/solution = 0.000900 mol/0.00700L = 0.129 mol/L=
= 0.129 M
In the presence of a strong base, the following reaction between (CH3)3CCl and OH- occurs: (CH3)3CCl + OH- → (CH3)3COH + Cl- Studies have suggested that the mechanism for the reaction takes place in 2 steps: Step 1) (CH3)3CCl → (CH3)3C+ + Cl- (slow) Step 2) (CH3)3C+ + OH- → (CH3)3COH (fast) What is the rate law expression for the overall reaction? Group of answer choices
Answer:
D. rate = k [(CH3)3CCl]
Explanation:
(CH3)3CCl + OH- → (CH3)3COH + Cl-
The mechanisms are;
Step 1)
(CH3)3CCl → (CH3)3C+ + Cl- (slow)
Step 2)
(CH3)3C+ + OH- → (CH3)3COH (fast)
In kinetics, the slowest step is the ratee determining step.
For a given reaction;
A → B + C, the rate law expression is given as;
rate = k [A]
In this problem, from step 1. The rate expression is;
rate = k [(CH3)3CCl]
Give the characteristic of a zero order reaction having only one reactant. a. The rate of the reaction is not proportional to the concentration of the reactant. b. The rate of the reaction is proportional to the square of the concentration of the reactant. c. The rate of the reaction is proportional to the square root of the concentration of the reactant. d. The rate of the reaction is proportional to the natural logarithm of t
Answer:
a. The rate of the reaction is not proportional to the concentration of the reactant.
Explanation:
The rate expression for a zero order reaction is given as;
A → Product
Rate = k[A]⁰
[A]⁰ = 1
Rate = K
GGoing through the options;
a) This is correct because in the final form of the rate expression, the rate is independent of the concentration.
b) This option is wrong
c) This option is also wrong
d) Like options b and c this is also wrong becaus ethere is no relationship between either the concentration or t.
A weather balloon is inflated to a volume of 27.6 L at a pressure of 755 mmHg and a temperature of 29.9 ∘C. The balloon rises in the atmosphere to an altitude where the pressure is 385 mmHg and the temperature is -14.1 ∘C. Assuming the balloon can freely expand, calculate the volume of the balloon at this altitude.
Answer: The volume of the balloon at this altitude is 46.3 L
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 755 mm Hg
[tex]P_2[/tex] = final pressure of gas (at STP) = 385 mm Hg
[tex]V_1[/tex] = initial volume of gas = 27.6 L
[tex]V_2[/tex] = final volume of gas = ?
[tex]T_1[/tex] = initial temperature of gas = [tex]29.9^0C=(29.9+273)K=302.9K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]-14.1^0C=((-14.1)+273)K=258.9K[/tex]
Putting all the values we get:
[tex]\frac{755\times 27.6}{302.9}=\frac{385\times V_2}{258.9}[/tex]
[tex]V_2=46.3L[/tex]
Thus the volume of the balloon at this altitude is 46.3 L
The partial Lewis structure that follows is for a hydrocarbon molecule. In the full Lewis structure, each carbon atom satisfies the octet rule, and there are no unshared electron pairs in the molecule. The carbon-carbon bonds are labeled 1, 2, and 3.
A) How many hydrogen atoms are in the molecule?
B) Rank the carbon-carbon bonds in order of increasing bond length.
C) Which carbon-carbon bond is the strongest one?
Answer:
A) How many hydrogen atoms are in the molecule?
The lock-and-key model and the induced-fit model are two models of enzyme action explaining both the specificity and the catalytic activity of enzymes. Following are several statements concerning enzyme and substrate interaction. Indicate whether each statement is part of the lock-and-key model, the induced-fit model, or is common to both models.
a. Enzyme conformation changes when it binds the substrate so the active site fits the substrate.
b. Substrate binds to the enzyme at the active site, forming an enzyme-substrate complex.
c. Enzyme active site has a rigid structure complementary
d. Substrate binds to the enzyme through noncovalent interactions
Answer:
The lock-and-key model:
c. Enzyme active site has a rigid structure complementary
The induced-fit model:
a. Enzyme conformation changes when it binds the substrate so the active site fits the substrate.
Common to both The lock-and-key model and The induced-fit model:
b. Substrate binds to the enzyme at the active site, forming an enzyme-substrate complex.
d. Substrate binds to the enzyme through non-covalent interactions
Explanation:
Generally, the catalytic power of enzymes are due to transient covalent bonds formed between an enzyme's catalytic functional group and a substrate as well as non-covalent interactions between substrate and enzyme which lowers the activation energy of the reaction. This applies to both the lock-and-key model as well as induced-fit mode of enzyme catalysis.
The lock and key model of enzyme catalysis and specificity proposes that enzymes are structurally complementary to their substrates such that they fit like a lock and key. This complementary nature of the enzyme and its substrates ensures that only a substrate that is complementary to the enzyme's active site can bind to it for catalysis to proceed. this is known as the specificity of an enzyme to a particular substrate.
The induced-fit mode proposes that binding of substrate to the active site of an enzyme induces conformational changes in the enzyme which better positions various functional groups on the enzyme into the proper position to catalyse the reaction.