Answer:
The best existing methods of control—artemisinin-based drug treatment and insect control with chemical sprays and treated bednets—can reduce the burden of disease substantially, and can even eliminate the disease in some regions,
hope this will help you more
I need help with the practice question at the bottom. Thank you.
As the gas expands on the surrounding, work is done by the system.
Therefore, W= -279J
Absorbtion of heat,q= +216J
∆U=q+W = (216-279)J= -63J
if salt and sand is mixed with distilled water, what will be the residue and what will be the filtrate?
Answer:
salt and sand
Explanation:it is what it is
How do forces between particles in gases compare to forces in the other states of matter?
The forces in gases are weaker than forces in solids and liquids.
Because they have more kinetic energy that overcomes the force of attraction.
What is unit? Write down the units of mass, temperature and power
Explanation:
a single thing, person, or group forming part of a whole There are 36 units in my apartment building. the least whole number : one. a fixed quantity (as of length, time, or value) used as a standard of measurement An inch is a unit of length.mass=kilogram (kg)
temperature=kelvin
power=watt
hope it helps
stay safe healthy and happy..Give the number of lone pairs around the central atom and the molecular geometry of SCl2. Multiple Choice 3 lone pairs, linear 1 lone pair, bent 3 lone pairs, bent 0 lone pairs, linear 2 lone pairs, bent
Answer:
2 lone pairs, bent
Explanation:
According to the Valence Shell Electron Pair Repulsion Theory, the number of electron pairs on the valence shell of the central atom in a molecule influences the shape of the molecule.
The presence of lone pairs on the valence shell of the central atom causes the observed molecular geometry to deviate from the ideal geometry predicted on the basis of the valence shell electron pair repulsion theory.
SCl2 has four regions of electron density. This means that its electron domain geometry is tetrahedral. However, there are two lone pairs on the valence shell of the central atom hence the observed molecular geometry is bent.
Determine whether each phrase describes carboxylic acids or esters.
a. Usually have a sour odor _____________
b. Notable for their pleasant fragrances ___________
c. Do not form hydrogen bonds amongst themselves and have higher vapor pressure _____________
d. Their reactions with base are known as neutralizations ____________
e. Their reactions with base are known as saponifications _____________
a laser emits light with a frequency of 4.69 x 10 to the 14th power s - 1 calculate the wavelength of this light.
Answer:
6.40x10^-7
Explanation:
answer with work is attached.
chemistry help!
This mysterious gas has a volume of 4.35 L and a pressure of 1.20 atm. If the pressure is changed to 0.95 atm, what will the new volume be? How do i set up this problem and solve it?
Refer to the attachment.
Hope this helps you...
A beaker is filled to the 500 mL mark with alcohol. What increase in volume (in mL) does the beaker contain when the temperature changes from 5° C to 30° C? (Neglect the expansion of the beaker, evaporation of alcohol and absorption of water vapor by alcohol.) The volume coefficient of expansion γγ for alcohol = 1.12 x 10-4 K-1
Answer:
"1.4 mL" is the appropriate solution.
Explanation:
According to the question,
[tex]v_0=500[/tex][tex]\alpha =1.12\times 10^{-4}[/tex][tex]\Delta \epsilon = 25[/tex]Now,
Increase in volume will be:
⇒ [tex]\Delta V = \alpha\times v_0\times \Delta \epsilon[/tex]
By putting the given values, we get
[tex]=1.12\times 10^{-4}\times 500\times 25[/tex]
[tex]=1.12\times 10^{-4}\times 12500[/tex]
[tex]=1.4 \ mL[/tex]
following this list of common polyatomic ions what would be the charge for aluminum nitrate?
Nitrate NO3
Phosphate PO43,
Sulfate SO4 -2
acetate C2H3O2-1
Ammonium NH4.
Chromate CrO4-2
Carbonate C03-2
Dichromate CrO7-2
Permanganate MnO4-1
What would be the correct answer for Aluminum nitrate
Answer:
Nitrate NO3
here's your answer, hope it helps you
(4.184 J——> 1 calorie ? Take your answer from number 1 and convert to the answer into calories?
Answer:
There are 1.195 calories in 5 J.
Explanation:
The relation between calorie and Joules is as follow :
4.184 J = 1 calorie
or
1 J = (1/4.184) calorie
Let the taken number is 5 J
So,
5 J = (5/4.184) calorie
5 J = 1.195 calorie
So, there are 1.195 calories in 5 J.
What is the mass number of an ion with 106 electrons, 157 neutrons, and a +1 charge?
Answer:
264 g/mol
Explanation:
#electrons equal #protons = 106
Plus 1 charge => m protons = 106 + 1 = 107
Mass number: 107 + 157 = 264 g/mol
A 250 mL sample of gas at 1.00 atm and has the temperature increased to and the volume increased to 500 mL. What is the new pressure
Answer:
0.53atm = P2
Explanation:
Gas at 1.00atm and 20°C. Temperature increased to 40°C...
We can solve this question using combined gas law:
P1*V1 / T1 = P2*V2 / T2
Where P is pressure, V volume and T absolute temperature of 1, initial state and 2, final state.
Compunting the values of the problem:
P1 = 1.00atm
V1 = 250mL
T1 = 20°C + 273.15 = 293.15K
P2 = ?
V2 = 500mL
T2 = 40°C + 273.15 = 313.15K
1.00atm*250mL / 293.15K = P2*500mL / 313.15K
0.53atm = P2
I mix together 50.0 mL of 0.100 M NaIO3, 50.00 mL of 0.100 M NaOH, and 10.0 mL of 0.100 M HIO3. What is the pH of the mixture
Answer:
pH = 12.66
Explanation:
The HIO3 reacts with NaOH as follows:
HIO3 + NaOH → H2O + NaIO3
The moles of HIO3 and NaOH added are:
Moles HIO3:
0.0100L * (0.100mol / L) = 0.00100 moles HIO3
Moles NaOH:
0.05000L * (0.100mol / L) = 0.00500 moles NaOH
As moles NaOH > Moles HIO3, the moles of NaOH that remain are:
0.00500mol - 0.00100mol = 0.00400 moles NaOH.
After the reaction you will have only NaOH and NaIO3. As NaIO3 is a salt, the pH of the solution is determined by only NaOH. Its concentration is:
Moles NaOH: 0.00500 moles NaOH
Volume: 50.0mL + 50.0mL + 10.0mL = 110.0mL = 0.110L
Molarity: 0.0455M NaOH = [OH-]
pOH = -log [OH-] = 1.34
pH = 14 - pOH
pH = 12.66pH is the measure of the hydrogen or the hydronium ion in an aqueous solution. The pH of the mixture containing sodium hydroxide is 12.66.
What is pH?pH is the potential of the hydrogen and is given as a negative log of the hydrogen concentration in the aqueous solution.
The balanced chemical reaction can be shown as:
[tex]\rm HIO_{3} + NaOH \rightarrow H_{2}O + NaIO_{3}[/tex]
Moles of iodic acid are calculated as:
[tex]\begin{aligned} \rm moles &= \rm molarity \times volume\\\\&= 0.100 \;\rm M \times 0.0100 \;\rm L \\\\&= 0.00100\;\rm moles\end{aligned}[/tex]
Moles of sodium hydroxide are calculated as:
[tex]\begin{aligned} \rm moles &= \rm molarity \times volume\\\\&= 0.100 \;\rm M \times 0.05000 \;\rm L \\\\&= 0.00500\;\rm moles\end{aligned}[/tex]
The remaining moles of sodium hydroxide are 0.00500mol - 0.00100mol = 0.00400 moles.
The pH of the mixture will be determined by sodium hydroxide, as sodium iodate is a salt.
The molar concentration of sodium hydroxide is calculated as:
[tex]\begin{aligned} \rm M &= \rm \dfrac{moles}{volume}\\\\&= \dfrac{0.00500}{0.110}\\\\&= 0.0455 \;\rm M\end{aligned}[/tex]
pH is calculated as:
[tex]\begin{aligned} \rm pOH &= \rm -log[OH^{-}] = 1.34\\\\\rm pH &= \rm 14 - pOH\\\\\rm pH &= 12.66\end{aligned}[/tex]
Therefore, 12.66 is the pH of the mixture.
Learn more about pH here:
https://brainly.com/question/13539106
why might the melting point of the crystals obtained in this experiment be close to but below one of the reference melting points and melt slowly over several degrees
Answer: hello the experiment related to your question is missing but I will provide a more general answer within the scope of your question
answer :
presence of Impurities
Explanation:
The melting point of the crystals as obtained in the experiment will be close to but below reference melting points and will also melt slower because of the presence of impurities in the compound
Impurities alter the melting and freezing points from ideal freezing and melting points of compounds
What do phase diagrams demonstrate?
Select all that apply.
how the melting and boiling points of a substance change with pressure
how much heat will increase the temperature of a gram of a substance by 1°C
the pressure and temperature conditions in which a substance exists as a liquid, solid, or gas
a comparison of the temperature of a substance to the heat absorbed over time
Answer:
this answer is for first one
Explanation:
A higher evalations, where the atmospheric pressure is much lower, the boiling point increase with increased pressure up to the critical point where the gas and liquid properties become identical
Liquid ethyl mercaptan, C2H6S, has a density of 0.84 g/mL. Assuming that the combustion of this compound produces only CO2 , H2O, and SO2 , what masses of each of these three products would be produced in the combustion of 3.15 mL of ethyl mercaptan
Answer:
Mass CO2 = 3.75 grams
Mass H2O = 2.30 grams
Mass SO2 = 2.73 grams
Explanation:
Step 1: Data given
Density of Liquid ethyl mercaptan, C2H6S = 0.84 g/mL
Volume of ethyl mercaptan = 3.15 mL
Step 2: The reaction
2C2H6S + 9O2 → 4CO2 + 6H2O + 2SO2
Step 3: Calculate mass of ethyl mercaptan
Mass = Volume * density
Mass ethyl mercaptan = 3.15 mL * 0.84 g/mL
Mass ethyl mercaptan = 2.646 grams
Step 4: Calculate moles ethyl mercaptan
Moles = mass / molar mass
Moles ethyl mercaptan = 2.646 grams / 62.13 g/mol
Moles ethyl mercaptan = 0.04259 moles
Step 5: Calculate moles of other products
For 2 moles ethyl mercaptan we need 9 moles O2 to produce 4 moles CO2, 6 moles H2O and 2 moles SO2
For 0.04259 moles we need 0.1917 moles O2 to produce:
2*0.04259 = 0.08518 moles CO2
3*0.04259 = 0.1278 moles H2O
1*0.04259 = 0.04259 moles SO2
Step 6: Calculate mass produced
Mass = moles * molar mass
Mass CO2 = 0.08518 moles * 44.01 g/mol
Mass CO2 = 3.75 grams
Mass H2O = 0.1278 moles * 18.02 g/mol
Mass H2O = 2.30 grams
Mass SO2 = 0.04259 moles * 64.07 g/mol
Mass SO2 = 2.73 grams
The Li2+ ion is very similar to the hydrogen atom, in that it has one electron and energy levels similar
to the hydrogen atom. However, the relation = − (
1
2 −
1
2) cannot be used for this ion but
rather the relation = −2+ (
1
2 −
1
2) where the constant 2+=1.96x10-17J.
Use this relation to determine the third ionization energy, which is energy required to remove the last
electron from a Li2+ ion in kJ/mol, if the ion starts off in the ground state (Li2+ → Li3+
+ e-
).
Which of the five type of equilibrium problems best applies to this question: Consider the following reaction at equilibrium. What effect will reducing the volume of the reaction mixture have on the system
Answer:
d
Explanation:
Og is the noble gas after Rn. To go from [Rn] to [Og], you must fill four subshells (s, p, d, and f) with a total of 32 electrons. Thus, the atomic numbers of 6th and 7th period elements of the same group differ by 32.
a. To go from [Og] to the next noble gas, however, you would theoretically fill five subshells (s, p, d, f, and g). How many electrons are needed to fill all five subshells?
b. Element 106 in the periodic table is Sg Determine the atomic number of the element just below Sg in the periodic table.
Answer:
See explanation
Explanation:
Since we have to fill five subshells in moving from Og to the next noble gas in the eight period, we have to know the maximum electrons contained in each of those subshells;
s= 2, p=6, d= 10, f= 14, g = 18
This means that we need a total of 50 electrons to fill all the five subshells.
Hence, the element just below Sg in the eight period will have an atomic number of 156.
determine the mass in grams of 3.75 x 10^21 atoms of zinc. (the mass of one mole of zinc is 65.39 g)
Answer: The mass in [tex]3.75 \times 10^{21}[/tex] atoms of zinc is 0.405 g.
Explanation:
Given: Atoms of zinc = [tex]3.75 \times 10^{21}[/tex]
It is known that 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms. So, the number of moles in given number of atoms is as follows.
[tex]Moles = \frac{3.75 \times 10^{21}}{6.022 \times 10^{23}}\\= 0.622 \times 10^{-2}\\= 0.0062 mol[/tex]
As moles is the mass of a substance divided by its molar mass. So, mass of zinc (molar mass = 65.39 g/mol) is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\0.0062 mol = \frac{mass}{65.39 g}\\mass = 0.405 g[/tex]
Thus, we can conclude that the mass in [tex]3.75 \times 10^{21}[/tex] atoms of zinc is 0.405 g.
How much would the freezing point of water decrease if 4 mol of sugar were added to 1kg of water?
Answer:
7.44 C is the answer of the question.
Explanation:
An object was measured by a worker as 14.6cm long, however, the manufacturer specifications list the length of the object at 14.4cm. What is the percent error in the worker's measurement? A. 1.39%
B. 1.37%
it's 0.2cm different from the expected value, wich was 14.6cm
how many percent that are is calculated in the screenshot.
rounded it's 1.37%
Explain why ionic compounds have higher boiling points than covalent compounds.
Answer:
because the have stronger electrostatic force
Which is NOT an indicator of a chemical change?
Answer:
The choice that is not an indicator of a chemical change is "State of matter changes". More common than not, chemical reactions produce energy in the form of light or heat. Along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid).
Explanation:
Describe how you would prepare your assigned ester from a carboxylic acid and an alcohol. You do not need to include a detailed procedure, but you should include any necessary reagents or catalyst (solvents are not needed).
Answer:
The general preparation of esters( for example ethyl ethanoate) is through a process known as ESTERIFICATION.
Explanation:
The formation of an ester by the reaction between an alkanol and an acid is known as esterification. This reaction is extremely slow and reversible at room temperature, and is catalyzed by a high concentration of hydrogen ions.
In the preparation of one of the simpler esters known as ETHYL ETHANOATE the reactants include ethanol(an alcohol) and glacial ethanoic acid(a carboxylic acid) in the presence of concentrated tetraoxosulphate VI acid as a CATALYST. Note that, a catalyst is any substance that is able to increase the rate of a chemical reaction.
The mixture is warmed in a water bath( hot but not boiling) for about 25 minutes. The mixture is poured into a beaker partially filled with a sodium or calcium chloride to remove interacted ethanol. The ethyl ETHANOATE floats on the mixture as oily globules.
Which statement is true about molarity and percent by mass? (3 points)
They have the same unit.
They are inversely related.
They are different units of dilution.
They are different units of concentration.
Answer:
The guy above used photoshop here is the actual answer.
Explanation:
The true statements about molarity and percent by mass is that they are the different units of concentration
What is concentration?Concentration of any substance present in any solution guves idea about their relative amount in that and it can de described in terms of molarity and percent by mass.
Molarity is define as the moles of solute present in per unit volume of the solution and has a unit of mol/L.Percent by mass is define as the mass of solute present in total mass of solution and it is a unit less quantity.They both gives idea about the concentration, not of the dillutions.They are not inversely related else they are directly related to each other as they are depends on the moles or mass of solute.Hence, molarity and percent by mass are the different units of concentration and directly related to each other.
To know more about molarity & percent mass, visit the below link:
https://brainly.com/question/26150306
A major component of gasoline is octane when octane is burned in air it chemically reacts with oxygen to produce carbon dioxide and water what mass of carbon dioxide is produced by the reaction of oxygen
gasoline is the chemical that is coming out of the air
Predict the product when 2-methylbutanol is oxidised with pyridium chlorochromate in dichloromethane (PCC/CH2C12) a. CH3CH2CH(CH3)COOH b. CH3CH2CH2CH(CH3)CHO C. CH3CH2CH(CH3)CHO d. CH3CH2CH(CH3)OH 8:40 PM Type a message
Answer:
c. CH3CH2CH(CH3)CHO
Explanation:
Hello there!
In this case, according to the process for the one-step oxidation of a primary alcohol with a moderately strong oxidizing agent like pyridinium chlorochromate (PCC), whereby an aldehyde is produced, we infer that the corresponding product will be 2-methylbutanal, which matches with the choice c. CH3CH2CH(CH3)CHO according to the following reaction:
[tex]CH_3CH_2CH(CH_3)CH_2OH\rightarrow CH_3CH_2CH(CH_3)COH[/tex]
Regards!
What is the gravitational potential energy of a 1500-kg truck resting on top of a 550-m hill on earth?( earth’s gravitational pull is 9.8m/s2).
Answer:
E = 8085 kJ
Explanation:
Given that,
The mass of a truck, m = 1500 kg
Height, h = 550 m
We need to find the gravitational potential energy of the truck. It can be calculated as follows :
[tex]E=mgh[/tex]
Put all the values,
[tex]E=1500\times 9.8\times 550\\\\E=8085000\ J\\\\or\\\\E=8085\ kJ[/tex]
So, the gravitational potential energy is 8085 kJ.
