Answer:
The correct answer is - 800.
Explanation:
Given:
Total amount = ? or assume x
spend in buying birthday item = 3/4 of x
given to sister = 1/5 of x
remaining to mother = 40
solution:
the remaning amount = x- (3x/4+x/5) = 4=
=> x- 19x/20 = 40
=> x = 20*40
=> x = 800
thus, the correct answer is = 800
PLZ HELP ME ASAP!!!!(I WILL ALSO MARK BRAINLIEST!!!)
(True or False) A cold front often signals sunny warm weather.
PLEASE HELP ITS DUE SOON AND I DONT UNDERSTAND
How many grams of KClO3 must be decomposed to produce 3.45 L of oxygen at STP with a 75.3% yield? 2 KClO3(s) à 2 KCl(s) + 3 O2(g)
Question 10
Which of the following fuels is most likely to perform poorly in cold climates?
A. Petrol
B. Petrodiesel
C. Biodiesel made from plant oil.
D. Biodiesel made from animal fat.
Answer:
C. Biodiesel made from plant oil.
Explanation:
The type of vegetable oil used in production greatly affects the performance of biodiesel in the winter. The less saturated the fat, the better the performance in winter time. Canola oil works very well for low temperature biodiesel, and palm oil is among the worst for cold weather performance.
Hope this helped!!!
help asap please, What does Newton's law of gravitation state that two masses will do?
always fall
not have any affect on each other
attract each other
repel each other
Answer:
According to Newton's law of gravitation two objects attract each other
Answer: C. Attract each other!
Explanation:
Use the equation qliquid = m × c × ΔT to calculate the heat gained by the cold liquid. Use the specific heat for the liquid you selected.
Use the equation qwater = m × c × ΔT to calculate the heat lost by the hot water. Show your work using the problem-solving method shown in previous rubrics.
Complete question :
Use the equation qliquid = m × c × ΔT to calculate the heat gained by the cold liquid. Use the specific heat for the liquid you selected.
m = 248.9 g ; T = 72.6°C ; C = 3.73 j/g°C
Use the equation qwater = m × c × ΔT to calculate the heat lost by the hot water. Show your work using the problem-solving method shown in previous rubrics.
M = 237 g ; T = 41.2°C ; C = 4.184 j/g°C
Answer:
Quantity of heat gained = 67401.6 Joules
Quantity of heat lost by hot water = 40854.25 Joules
Explanation:
The heat gained by cold liquid :
Q = m × c × ΔT
m = 248.9 g ; T = 72.6°C ; C = 3.73 j/g°C
Q = 248.9 * 3.73 * 72.6
Q = 67401.6 Joules
Quantity of heat gained = 67401.6 Joules
Heat lost by hot water :
m × c × ΔT
M = 237 g ; T = 41.2°C ; C = 4.184 j/g°C
Q = 237 * 41.2 * 4.184
Q = 40854.25 Joules
Quantity of heat lost by hot water = 40854.25 Joules
how we can remove temporary hardness of water?and write the chemical reaction?
Answer:
it can be removed
1. by boiling
Ca(HCO3)2 > CaCO3 + H2O +CO2
2. by treating with calcium hydroxide
Draw curved arrows to show electron reorganization for the mechanism step below. (For a resonance-stabilized anion, draw a single resonance form with the negative charge on oxygen, not on carbon.) Make the ends of your arrows specify the origin and destination of reorganizing electrons.
Answer:
Explanation:
Dear student, this question appears to be incomplete but in the diagram attached below, I have carefully drawn out the required organic structure.
The aim of this question is to show the mechanism of the given structure and to point out the resonance structure.
The first diagram shows the complete part (i.e. the structure of the organic compound) and its major product(answer).
The second diagram shows the mechanism by which we arrived at the major product.
From the second diagram attached below, the -oxo substituent of the methanol attacks the hydrogen atom as shown below, leading to the formation of the enolate ion (a resonance stabilized anion).
However, this is because the alpha carbon attaches to the hydrogens readily leaves as H⁺ to yield an enolate ion as a result of -C- that is doubly bonded to oxygen (an Electron withdrawing group).
Kindly check out the images attached below to see the mechanism.
Calculate the pH when 64.0 mL of 0.150 M KOH is mixed with 20.0 mL of 0.300 M HBrO (Ka = 2.5 × 10⁻⁹)
Answer:
The answer is "12.06"
Explanation:
Given:
[tex]M(HBrO) = 0.3\ M\\\\V(HBrO) = 20 \ mL\\\\M(KOH) = 0.15 \ M\\\\V(KOH) = 64 \ mL[/tex]
[tex]\to mol(HBrO) = M(HBrO) \times V(HBrO) = 0.3 M \times 20 mL = 6 \ mmol\\\\\to mol(KOH) = M(KOH) \times V(KOH)= 0.15 M \times 64 mL = 9.6 mmol[/tex]
6 mmol of both will react
excess KOH remaining[tex]= 3.15 \ mmol[/tex]
Volume[tex]= 20 + 64 = 84 \ mL[/tex]
[tex][OH^{-}] = \frac{ 9.6 \ mmol}{84\ mL} = 0.01142\ M[/tex]
use:
[tex]pOH = -\log [OH^-][/tex]
[tex]= -\log (1.142\times 10^{-2})\\\\= 1.94[/tex]
use:
[tex]PH = 14 - pOH[/tex]
[tex]= 14 - 1.94\\\\= 12.06[/tex]
The pH of the resulting solution is 12.63.
The equation of the reaction is;
HBrO(aq) + KOH(aq) ------> KOBr(aq) + H2O(l)
Number of moles of KOH= 64/1000 × 0.150 M = 0.0096 moles
Number of moles of HBrO = 20/1000 × 0.300 M = 0.0060 moles
Number of moles of excess base = 0.0096 moles - 0.0060 moles = 0.0036 moles
Total volume of solution = 64.0 mL + 20.0 mL = 84 mL = 0.084 L
Molarity of excess base = 0.0036 moles/0.084 L = 0.043 M
pOH = -log[OH-]
pOH = -log[ 0.043 M]
pOH = 1.37
pH + pOH = 14
pH = 14 -pOH
pH = 14 - 1.37
pH = 12.63
Learn more: https://brainly.com/question/11897796
How many atoms are in 57.5 liters of xenon gas at STP
Answer:
1.55 × 10²⁴ atoms Xe
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesSTP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 57.5 L Xe at STP
[Solve] atoms Xe
Step 2: Identify Conversions
[STP] 22.4 L = 1 mol
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 57.5 \ L \ Xe(\frac{1 \ mol \ Xe}{22.4 \ L \ Xe})(\frac{6.022 \cdot 10^{23} \ atoms \ Xe}{1 \ mol \ Xe})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 1.54583 \cdot 10^{24} \ atoms \ Xe[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.54583 × 10²⁴ atoms Xe ≈ 1.55 × 10²⁴ atoms Xe
A 15.0 mL solution of 0.10 M Fe(NO3)3 reacts with K2C204 according to the reaction 2 Fe(NO3)3 + 3 K2C2O4 → Fe2 (C2O4)3 + 6 KNO3 . What volume of 0.30 M K2C2O4 is needed to react completely?
The volume of 0.30 M potassium chromate needed to react with 15 ml of 0.10 M ferric nitrate is 5 ml.
What is molarity?Molarity of a solution is the ratio of its number of moles of solute to the volume of solution in liter. It is the common term used to express the concentration of a solution.
Let V1 and M1 be the volume and molarity of solution 1 and V2 and M2 that of solution 2 which are reacting together.
Thus, V1 M1 = V2 M2.
The volume of 0.30 M potassium chromate is calculated as follows:
volume = (15 ml × 0.10 M) / 0.30 M = 5 ml.
Therefore, the volume of the potassium chromate solution is 5 mL.
To find more on molarity, refer here:
https://brainly.com/question/8732513
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Which of the solids in the following set should you test to investigate for the effects of ANIONS on pH? Will give brainliest
-KClO
-RbF
-AlBr3
-Rb2SO3
-CrCl3
Answer:
KCIO
Explanation:
the only reason is because I looked online and the meaning for that is potassium hypochlorite my guy so if this is not right then I'm sorry but good luck.
Collisions app covalent bonding level 15
Answer: change the nitrogen with oxygen for the first part then have the nitrogens collided instead of oxygens in the last part - not sure if my terminology is correct but here is the pic to show!
Explanation:
heat would best be transferred by conduction between
A. a candle and the air
B. an oven and a glass dish
C. a stove and a copper pot
D. water and a wooden spoon
Answer:
C. or B.
Explanation:
The reason I chose c best, is when your cooking something with a pot with food in it max heat in about 5 minutes, the handle starts to get warmer every minute. This is conduction, where the heat transfers from the very bottom all the way to the very edge of something that is heated at a certain temperature.
the solubility of PbSO4 is 0.048g/Liter. what is the Ksp of PbSO4? (MMPbSO4 = 303.3)
Answer:
Ksp of PbSO4 is 2.5 *10^-8
Explanation:
Given -
Solubility of PbSO4 = 0.048g/Liter
[Pb+2] * [SO42-] = mass/molecular weight of PbSO4
[Pb+2] * [SO42-] = 0.048g/Liter/303.3g/mol = 0.000158 M
Concentration of PbSO4 = moles/volume = 0.000158 M/1L = 0.000158 M
Ksp = [Pb+2] * [SO42-]
ksp = 0.000158 * 0.000158 = 2.5 *10^-8
calculate the percentage of CL in AL(CLO3)3
Answer:
38.4%
Explanation:
We'll begin by calculating the molar mass of Al(ClO₃)₃. This can be obtained as follow:
Molar mass of Al(ClO₃)₃
= 27 + 3[35.5 + (16×3)]
= 27 + 3[35.5 + 48]
= 27 + 3[83.5]
= 27 + 250.5
= 277.5 g/mol
Next, we shall determine the mass of Cl in Al(ClO₃)₃. This can be obtained as follow:
Mass of Cl in Al(ClO₃)₃ = 3 × Cl
= 3 × 35.5
= 106.5 g
Finally, we shall determine the percentage of Cl in Al(ClO₃)₃. This can be obtained as follow:
Mass of Cl in Al(ClO₃)₃ = 106.5 g
Mass of Al(ClO₃)₃ = 277.5 g
Percentage of Cl =?
Percentage of Cl = mass of Cl / mass of Al(ClO₃)₃ × 100
Percentage of Cl = 106.5 / 277.5 × 100
Percentage of Cl = 38.4%
When 148. mg of a certain molecular compound X are dissolved in 75.g of cyclohexane (CH), the freezing point of the solution is measured to be 59 'C. Calculate the molar mass of X If you need any additional information on cyclohexane, use only what you find in the ALEKS Data resource. Also, be sure your answer has a unit symbol, and is rounded to l significant digit. XS ?
Answer: The molar mass of X is 61.3g/mol
Explanation:
Depression in freezing point is given by:
[tex]\Delta T_f=K_f\times m[/tex]
[tex]\Delta T_f=T_f^0-T_f=(6.55^0C-5.9^0C)=0.65^0C[/tex] = Depression in freezing point
[tex]K_f[/tex] = freezing point constant = [tex]20.2^0C/mol[/tex]
m= molality = [tex]\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Mass of solvent in Kg}}[/tex]
where,
Now put all the given values in this formula, we get
[tex]0.65^0C=20.2°C/m\times frac{0.148g}}{M\times 0.075kg}[/tex]
[tex]M=61.3g/mol[/tex]
Thus molar mass of X is 61.3g/mol
Acid-catalyzed addition of water to an alkene yields an alcohol with Markovnikov regiochemistry.
a. True
b. False
Answer:
True
Explanation:
Markovnikov rule states that the negative part of the addendum is added to the carbon atom having the least number of hydrogen atoms.
This means that during acid-catalyzed addition of water to an alkene, the -OH is added to the more substituted carbon atom while the -H is added to the least substituted carbon atom in obedience to Markovnikov regiochemistry.
Answer:
a. True
Explanation:
Acid-catalyzed addition of water to an alkene yields an alcohol with Markovnikov regiochemistry. The electrophilic H+ adds to the sp2 carbon with the most hydrogens to yield the most stable carbocation intermediate, which then adds water to give the product alcohol.
Calculate the value of the equilibrium constant for the following system, where the concentrations of reactants and products are: [NO]=1.2x10^-3M , [NO2]=1.5x10-^1M , [N2O]=2.4x10^-3M
Answer:
The equilibrium constant is 2.08x10⁵
Explanation:
Based on the reaction:
3NO ⇄ N₂O + NO₂
The equilibrium constant, k, is defined as:
k = [NO₂] [N₂O] / [NO]³
Where the [] is the molarity in equilibrium of each specie.
Computing te values of the problem:
k = [1.5x10⁻¹M] [2.4x10⁻³M] / [1.2x10⁻³M]³
k = 2.08x10⁵
The equilibrium constant is 2.08x10⁵
The different unit cell types have a different packing efficiency. The simple cubic has the least efficient packing and the face-centered cubic has the most efficient packing (sometimes the face-centered cubic is called cubic closest packing). You can determine what percent of the unit cell is occupied by (1) determining the volume of the whole unit cell and (2) determining the volume of the occupied space by the atoms in the unit cell. Remember that the volume of a cube is V
Answer:
The answer is "52.8".
Explanation:
Please find the graph file in the attachment.
They have the atoms in 8 corners with one unit cell in an one so mesh (SCC).
Atoms throughout the corner contribute [tex]\frac{1}{8}[/tex]to both the cell unit
Atom number per SCC unit cell, [tex]Z = (8 \times \frac{1}{8}) = 1[/tex]
Let 'r' become the atom's radius. [tex]r = 3.43\times 10^{-8}\ \ cm[/tex]
We can see from the diagram that edge length [tex]AB = a = 2r[/tex]
[tex]Packing\ efficiency = \frac{(1 \ atom \ Volume \times Z)}{Volume \ of \ unit\ cell \times 100}\\\\[/tex]
[tex]= \frac{\frac{4}{3}\times \pi \times r^3 \times 1}{a^3 \times 100}\\\\=\frac{\frac{4}{3}\times \pi \times r^3 \times 1}{(2r)^3 \times 100} \\\\=\frac{\frac{4}{3}\times \pi \times( 3.43\times 10^{-8}cm)^3 \times 1}{(2\times 3.43\times 10^{-8}cm)^3 \times 100}\\\\= 52.8 \%[/tex]
A 1.4639-g sample of limestone is analyzed for Fe, Ca, and Mg. The iron is determined as Fe2O3 yielding 0.0357 g. Calcium is isolated as CaSO4, yielding a precipitate of 1.4058 g, and Mg is isolated as 0.0672 g of Mg2P2O7. Report the amount of Fe, Ca, and Mg in the limestone sample as %w/w Fe2O3, %w/w CaO, and %w/w MgO
Answer:
A) w/w % of Fe - 2.44%
B) w/w % of Mg - 4.590%
C) w/w % of Ca - 96%
Explanation:
A) w/w % of Fe in limestone as Fe2O3 = (Mass of Fe2O3 /Mass of limestone) x 100
0.0357/1.4639 X 100
= 2.438 =2.44
B) w/w % of Mg in limestone as Mg2P2O7 = (Mass of Mg2P2O7 /Mass of limestone) x 100
= 0.0672/1.4639 X 100
= 4.590
C) w/w % of Ca in limestone as CaSO4 = (Mass of CaSO4/Mass of limestone) x 100
= 1.4058/1.4639 X 100
= 96
Answer:Fe =1.71% Ma=0.99% Ca=28.24%
Explanation:
For the wild type (unmutated) enzyme, you measure a rate of p-nitrophenol release by the change in absorbance at 405 nm (for the slower phase only) of 0.216 (in a cuvette with a pathlength of 1 cm) over the course of two minutes. Use the Beer-Lambert Law to calculate the concentration of product released over this time; the extinction coefficient of p-nitrophenol at 405 nm is 18,000 M-1 cm-1.
Answer:
1.2x10⁻⁵M = Concentration of the product released
Explanation:
Lambert-Beer's law states the absorbance of a solution is directly proportional to its concentration. The equation is:
A = E*b*C
Where A is the absotbance of the solution: 0.216
E is the extinction coefficient = 18000M⁻¹cm⁻¹
b is patelength = 1cm
C is concentration of the solution
Replacing:
0.216 = 18000M⁻¹cm⁻¹*1cm*C
1.2x10⁻⁵M = Concentration of the product releasedIs it posible Count a grain of sand?explain
Answer:
Yes
Explanation:
As long as its a solid, you can count it. It will be hard, but possible.
Identify the term that matches each definition.
a. A characteristic that describes substances that evaporate readily, producing large amounts of vapors _________
b. The front vent of a fume hood, which helps maintain proper air circulation ___________
c. The glass panel in front of the fume hood that shields the user from fumes and other hazards ___________
d. The horizontal, flat area of a fume hood upon which experiments are carried out ________
Answer:
a. Volatile.
b. Air foil.
c. Sash.
d. Work surface.
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are;
I. Solid.
II. Liquid.
III. Gas.
Matching the terms with their respective definition, we have;
a. Volatile: A characteristic that describes substances that evaporate readily, producing large amounts of vapors.
b. Air foil: the front vent of a fume hood, which helps maintain proper air circulation.
c. Sash: the glass panel in front of the fume hood that shields the user from fumes and other hazards.
d. Work surface: the horizontal, flat area of a fume hood upon which experiments are carried out.
Suggest a possible
reason for the change
in sulfur dioxide levels
in North America and
Europe around
1970-1980.
Answer: a reason for this is fossil fuels
Explanation:
The reduction in SO2 is largely due to the implementation of the Acid Rain Program under the Clean Air Act through a cap and trade program for fossil-fuel powered plants.
Describe in your own words what is an air front is
Answer:
A front is a weather system that is the boundary separating two different types of air. One type of air is usually denser than the other, with different temperatures and different levels of humidity.
In the western U.S., ranchers aggressively killed wolves because they posed a threat to their cattle. As the wolf population declined, the deer population began increasing. As a result, the surrounding forest ecosystems experienced increasing damage. The large number of deer ravaged vegetation and destroyed young trees. The entire ecosystem became degraded until wolves became protected when they were determined to be an endangered species. Based on this information, what can you infer about the role of the wolves in this ecosystem? Please make it 3-5 sentences. Thank you so much
Answer:
Explanation:
You can make a couple of statements.
The wolves are preditors. They eat meat.The wolves hunt only 1 kind of food. They are not interested in young trees or grass (well not much anyway). If one species is allowed to get out of control, the entire ecosystem suffers because of it.This last statement only becomes true if man allows the hunted species that controlled the deer to regain good numbers. Man can be a blockhead sometimes; he learns slowly at times.Answer:
The wolves role in the ecosystem is to hunt/eat deer. In the question it states, "...ranchers aggressively killed wolves because they posed a threat to their cattle. As the wolf population declined, the deer population began increasing." It's clearly cause and affect, the wolves use to eat a lot of deer, then a large percentage of wolves died by the ranchers. The wolves role in the ecosystem is to hunt deer and help balance out animal to vegetation ratio.
Explanation:
Because i'm awesome lol
(Give me good ratings pleaseeeee.
Can you all go vote for Dacia Campbell for Brainly Educator of The Year!!!!!
It would mean a ton!!! Plus, I'll give your profile a big THANK YOU...I'll give Brainliest and you get 50 points! Please, please, please. Go vote for her!
Answer:
i voted her!!!!
Explanation:
7. Which object is excellent at holding onto electrons?
Answer:
Insulator
Explanation:
The glacier given in this picture is an example of which type?
Answer:
arctic glacier
Explanation:
Answer:
Explanation:
are there any choices to choose from?
if not a glacier is a type of frozen water compacted together...
if it doesnt have choices ill word it differently...
can u also tell me what is your unit about?
What do we call a large group of wind turbines used to generate electricity?
1)Wind Pack
2)Wind Mill
3) Wind Farm
4) Wind Plant
Answer:
your answer is 3 hope this helps you
Answer:
A wind farm
Explanation:
another word is a wind park