Answer:
i think D
Explanation:
A certain amount of NaOH is dissolved in certain kilograms of solvent and molality of the solution is 0.5 m. When the same amount of NaOH is dissolved in 100 grams of less solvent than initial then molality becomes 0.625 m. Determine the amount of NaOH and the initial mass of solvent.
[tex]\sf\bold{❍ Given:-}[/tex]
NaOH is dissolved in certain kilograms of solvent and molality of solution 0.5m.
Again , same among of NaOH is dissolved in 100 grams of solvent than initial , then molality becomes 0.625m.
$\space$
Now lets find the amount of NaOH and the initial mass of solvent.
Let,
$\sf\small{Initial\:Mass\:of\:solvent=y}$$\sf\small{Number\:of\:moles\:NaOH\:dissolved=x}$$\space$
$\sf\bold{ ❍ We\:know,}$
$\sf{Molality(m)=}$ $\sf\dfrac{No.of\:moles\:of\:solute}{No.of\:solvent\:in\:kg}$
$\space$
$\sf\bold{Putting\:the\:formula:-}$
$\space$
$\sf\huge\underline\bold{ ❍Case:1}$
$\space$
$\longmapsto$ $\sf\small{0.5}$ $\sf\dfrac{x}{y}$
$\space$
$\longmapsto$ $\sf{0.5y = x }$
$\space$
$\longmapsto$ $\sf{multiply\:by\:2→ y = 2x}$
$\space$
$\sf\huge\underline\bold{ ❍Case:2}$
$\space$
$\longmapsto$ $\sf\small{0.625}$ $\sf\small\dfrac{x}{y}$ = $\sf\dfrac{x}{y=100g}$
$\space$
$\longmapsto$ $\sf\small{0.625}$ $\sf\dfrac{x}{y-100/1000kg}$ = $\sf\dfrac{x}{y-0.1kg}$
$\space$
$\longmapsto$ $\sf{0.625(y-0.1kg)=x}$
$\space$
$\longmapsto$ $\sf{0.625y-0.0625=x}$
$\space$
$\sf\small\bold{By\:putting\:the\:value\:of \:"x" we\: get:}$
$\space$
$\longmapsto$ $\sf{0.625(2x)-0.0625 = x}$
$\space$
$\longmapsto$ $\sf{1.25x 0.0625 = x}$
$\space$
$\longmapsto$ $\sf{1.25x - x = 0.0625}$
$\space$
$\longmapsto$ $\sf{0.25x = = 0.0625}$
$\space$
$\longmapsto$ $\sf\small{x=}$ $\sf\dfrac{0.0625}{0.25}$= $\sf\bold{x=0.25}$
$\space$
$\sf{So,y=2(x)=2\times0.25=}$ $\sf\bold{y=0.5}$
$\space$
$\sf\small{Initial\:mass\:of\:solvent:0.5kg=500g}$
$\space$
$\sf{Now,}$
Amount of NaOH=
$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=x\times molar\:mass}$
$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=0.25\times 40=10}$
$\space$
$\sf\underline{\underline{ ⚘ Hence,amount\:of\:NaOH=10kg}}$
_______________________________
Help me ASPAPPPPPPPPP
Answer:
Explanation:
1. H2O
Lewis Dot:
See the attachment.
Note the б+ and б- signs on the H and O atoms, respectively. Those represent the slightly positive and slightly negative sides of the water molecule. Those slight charges on a single water molecule are attracted to their opposite charges on neighboring H2O molecules, as shown in the graphic. This interaction is what gives water it's cohesive properties.
3. The property of cohesion describes the ability of water molecules to be attracted to other water molecules. which allows water to be a "sticky" liquid.
The hydrogen bonds are attractions of electrostatic force. They arise due to the difference in charge between the slightly positive hydrogen ion and the slightly negative oxygen ion. Hydrogen bonds form between neighboring hydrogen and oxygen atoms of adjacent water molecules. The attraction between individual water molecules creates a bond known as a hydrogen bond, and it is what gives water it's cohesiveness, or ability to support water spiders, paper clips, and produces a loud noise in the event of a belly flop in a pool (including the yelp from the swimmer).
4. I'm not sure what is being asked for the two blanks. Water is polar and dissolves salts (ionic compounds) and hydrophilic molecules (water-loving molecules).
An inorganic salt is composed of 17.6% sodium, 39.7% chromium, and 42.8% oxygen. What is the empirical formula of this salt?
Unknown # 41
Flame Test Color: Lilac
Addition of HCl(aq): NR (No reaction)
Addition of HCl(aq) and BaCl2(aq): NR (No reaction)
Addition of HNO3(aq) and AgNO3(aq): Yellow precipitate
What is the unknown ionic compound molecular formula?
Answer:
KI
Explanation:
From the question, we can see that a qualitative analysis of the compound shows that it has a lilac flame colour. The lilac flame colour corresponds to the potassium ion (K^+).
Again, the test of addition of HNO3(aq) and AgNO3(aq) to a solution is a test for halogens. If the result is a green precipitate, then the ion present is the iodide ion (I^-).
Hence, the compound must be KI.
What is the formula for this compound?
1 atom of copper, 1 atom of sulfur, 4 atoms of oxygen
Answer:
The third one: [tex]CuSO_4[/tex]
Explanation:
Again you are going to want to look at a periodic table so you can determine the symbol of each atom.
The symbol for copper is Cu, the symbol for sulfur is S and the symbol for Oxygen.
There is 1 atom of copper in the compound
So we have Cu
There is 1 atom of sulfur in the compound
So we would have CuS
There are 4 atoms of oxygen in the compound
So we would have [tex]CuSO_4[/tex]
Note that the little number at the bottom left after each symbol indicates how many atoms of that element are in that compound.
hii pls help me to balance the equation and state the symbols thanksss
Answer:
I DID HOW I KNOW . I HOPE IT WILL HELP YOU :D
explain how wavelength is related to the energy of a wave
Answer: as the wavelength gets shorter, the energy increases; as the wavelength gets longer, the energy decreases. The greater the energy, the larger the frequency and the shorter (smaller) the wavelength.
Answer:
Just as wavelength and frequency are related to light, they are also related to energy. The shorter the wavelengths and higher the frequency corresponds with greater energy. So the longer the wavelengths and lower the frequency results in lower energy. The energy equation is E = hν.
Just saying, you have the wrong subject. This should be physics I think.Which description of salt is a physical property?
No combustion
Makes ionic bonds
Product of mixing acids and bases
Solid does not conduct electricity
Answer:
Solid and does not conduct electricity
Explanation:
a volume of .5650 will exert
Answer: A volume of .5650 what? And what unit will be considered?
Between what two elements does hydrogen bonding occur?
Answer:
it can occur between hydrogen and 3 other elements
Explanation:
These elements are:
Nitrogen
Oxygen
Flourine
difference Between phenol and dettol
PLZ HELP ME WITH MY WORK
Answer:High density
Explanation:
The metal doesn't remains gas at room tempreture, it doesn't have brittleness property and it is not poor conductor of electricity .But, it has high density .
Hope, it would be correct.
Figure 1
Describe how a frog grows. Why do you think the eggs are found in the water? Where do you think fertilization happens?
The process of fertilization occurs externally in frogs.
Stages of lifecycleA full growth of frog occurs when it passes through five stages of its life cycle. During a frog's metamorphosis, an egg will hatch and a tadpole appear in which the back legs emerge first, then front legs, and finally it become a full grown adult frog.
Eggs of frogA frog's eggs are found in water because they do not have a hard protective shell like birds and reptiles. The frog's eggs are covered with a glycoprotein, which helps to keep the eggs moist so that's why the frog lays its eggs in water in order to prevent them from drying.
FertilizationIn most species of frogs, fertilization occurs externally. The male frog grabs the female's back and fertilizes the eggs as the female frog releases the eggs. Those eggs which receives the sperm will fertilized so we can conclude that the process of fertilization occurs externally in frogs.
Learn more about growth here: https://brainly.com/question/25630111
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what is a tidal barrage
plase explaine
Answer:
A dam like structure used to capture energy from masses of water moving in or out of a bay of rivers due to tidal force is called tidal barrage.
Explanation:
It may help you to solve question.
pentanitrogen heptachloride formula
Answer:
Explanation:
this is the answer hope it helps!(:
The chemical formula of pentanitrogen heptachloride is N₅Cl₇ as it has 5 nitrogen atoms and 7 chlorine atoms.
What is chemical formula?
Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
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#SPJ2
I need answer for a. (ii) pls
Answer:
Stopwatch
Stopwatch is a time measuring tool.
How many grams of hydrogen gas are needed to react completely with 54.0 g of oxygen gas, given the following balanced chemical reaction:
2H2 +O2 --->2H2O
Answer:
6.75g of hydrogen will completely react with 54g of oxygen
Explanation:
An atom with 6 protons and 8 neutrons is an)
Answer: carbon (C)
Explanation:
help plz I don't understand the last 2 questions
Answer:
b) (i): 0.91 Amgstroms
(ii): 9.1 × 10^-11 Angstroms
(c): Volume = 20 Angstroms
Explanation:
• Let's first convert the units:
[tex]{ \rm{1 \:nanometre = 1 \times {10}^{ - 9} \: metres} } \\ { \rm{10 \: angstroms = 1 \times {10}^{ - 9} \: metres}} \\ { \rm{1 \: micrometer = 1 \times {10}^{ - 6} \: metres = 1000 \: nm}} \\ \\ { \rm{1 \: {nm}^{3} = 1000 \: {angstroms}^{3} }}[/tex]
Question (b)
(i)[tex]{ \rm{radius = \frac{diameter}{2} }} \\ \\ { \rm{radius = \frac{0.182}{2} }} \\ \\ { \rm{radius = 0.091 \: nm}} \\ \\ { \mathfrak{ answer{ : { \rm{radius = (0.091 \times 10) \: angstroms}}}}} \\ \\ { \rm{radius = 0.91 \: angstroms}}[/tex]
(ii)[tex]{ \rm{radius = 0.091 \: nm}} \\ \\ { \rm{radius = 0.091 \times( 1 \times {10}^{ - 9} ) \: metres}} \\ \\ { \rm{radius = 9.1 \times {10}^{ - 11} \: m }}[/tex]
(c)[tex]{ \rm{volume = (0.5 \times 0.2) \: nm \times 0.0002 \: micrometer}} \\ \\ { \rm{volume = 0.5nm \times 0.2nm \times (0.0002 \times 1000)nm}} \\ \\ { \rm{volume = 0.5 \times 0.2 \times 0.2 \: nm {}^{3} }} \\ \\ { \rm{volume = 0.02 \: nm {}^{3} }} \\ \\ { \rm{volume = (1000 \times 0.02) \: angstroms {}^{3} }} \\ \\ { \rm{volume = 20 \: angstroms}}[/tex]
A 1.732 g sample of iron is heated in air. It oxidizes to form a product with a mass of 2.205 g.
What is the empirical formula of the product?
Answer:
A 1.732 g sample of iron is heated in air. It oxidizes to form a product with a mass of 2.205 g. What is the empirical formula of the product? FeO 4. Caffeine is made of 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen by mass.
Explanation:
The empirical formula of the product formed by the reaction of iron and oxygen is FeO.
Let's consider the following generic chemical equation:
Fe + O₂ ⇄ FexOy
According to the law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products. The mass of O₂ that reacted, and remains in the oxide is:
[tex]mFe + mO_2 = mFexOy\\mO_2 = mFexOy - mFe = 2.205 g - 1.732 g = 0.473 g[/tex]
The oxide has 1.732 g of Fe and 0.473 g of oxygen and a total mass of 2.205 g. To determine the empirical formula, we need to calculate the percent composition.
[tex]\%Fe = \frac{mFe}{mFexOy} \times 100 \% = \frac{1.732 g}{2.205 g} \times 100 \% = 78.55\%[/tex]
[tex]\%O = \frac{mO}{mFexOy} \times 100 \% = \frac{0.473 g}{2.205 g} \times 100 \% = 21.45\%[/tex]
Now, we will divide each percentage by the atomic mass of the element.
[tex]Fe: 78.55/55.85 = 1.406\\O: 21.45/16.00 = 1.340[/tex]
Finally, we divide both numbers by the smallest one.
[tex]Fe: 1.406/1.340 \approx 1 \\O: 1.340/1.340 = 1[/tex]
The empirical formula of the product is FeO.
You can learn more about empirical formulas here: https://brainly.com/question/1363167
What’s is inside a cell? Crossword puzzle
ACROSS
2.package materials from the endoplasmic reticulum & send them to other parts of the cell
4.breaks down food & old cell parts
7.a stiff layer of nonliving material that surrounds a plant cell
8.jellylike material found within the cell membrane
10.found in plant cell; captures the sun’s energy to make food
12.genetic materials that carry information about the organism
13.moves materials throughout the cell
DOWN
1.produce proteins for the cell
3.a tiny structure inside a cell
5.controls all of the cell’s activities
6.produce most of the cells energy
7.controls substance that enter and leave the cell
9.creates ribosomes; found inside the..
11.stores water and waste inside the cell
How many total atoms are present in the compound: Mg(OH)_2
Answer:
In the compond Mg(OH)_2, 20 atoms are present.
Explanation:
What does an atom's period tell us?
Select one:
a. Number of protons
b. Number of shells
c. Number of valence
electrons
d. Number of electron
Stickleback fish are collected from a lake in Alaska. 600 from the sample are spineless, which is a recessive trait in the fish. 80 of the fish collected have spines. Calculate:
Answer:
Frequency of spinal trait in the population = 0.11
Explanation:
Given:
Total spineless trait = 600
Number of spinal trait = 80
Find:
Frequency of spinal trait in the population
Computation:
Total population = Total spineless trait + Number of spinal trait
Total population = 600 + 80
Total population = 680
Frequency of spinal trait in the population = Number of spinal trait / Total population
Frequency of spinal trait in the population = 80 / 680
Frequency of spinal trait in the population = 0.11
What is the number of atoms of oxygen in 0.1 mol of CuSO4.5H2O? & explain
ow does the food chain start? A Plant life uses energy from the sun to make food. B Insects like grasshoppers eat plant life. C Animals like rats eat insects. D Humans eat large animals and plant life
to make 400 gram solution with a mass by a mass concentration of 6 % how much salt and water you need to mix
Answer:
[tex]400 \div 6 \\ \\ [/tex]
What are the units of molar mass?
A. L/g
B. mol/g
C. g/L
D. g/mol
SUBST
Answer:
D - g/mol
step by step method
Can compound take part in chemical reaction?
Answer:
YES!
Explanation:
What mass of sugar and water is needed to make 40 g of 10% solution?
Answer
16g
Percent by mass= mass of solute/mass of solution * 100
Explanation: work out the equation