Answer:
D. see which items stick to the magnet
Explanation:
To predict which items are magnetic, the students will have to test whether or not each item is attracted to the magnet. Only objects that are magnetic stick to a magnet, so all of the items that stick to the magnet should be magnetic.
Hopefully that's helpful! :)
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=
$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=x\times molar\:mass}$
$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=0.25\times 40=10}$
$\space$
$\sf\underline{\underline{ ⚘ Hence,amount\:of\:NaOH=10kg}}$
_______________________________
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.
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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
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
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
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
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
9.0 mol of pure ammonia gas was injected into a 3.0 L flask and allowed to reach equilibrium according to the equation 2 NH3(g) = N2(g) + 3 H2(g). The equilibrium mixture was analyzed and found to contain 3.0 mol of hydrogen gas. Calculate the value of the equilibrium constant.
NOExplanation:
I DONT KNOW MATE
I need answer for a. (ii) pls
Answer:
Stopwatch
Stopwatch is a time measuring tool.
Precipitate WILL form if Silver Nitrate reacts with Iron (III) chloride
-true or false
Answer:
yes
Explanation:
3Ag(No3) (aq) +FeCl3(aq) -->Fe(NO3)3(aq)+3AgCl(s)
what is the material used to make plaster of paris?
Answer:
gypsum
Explanation:
gypsum is used to make plaster of Paris
Answer:
Simple squamous epithelium
This type of epithelia lines the inner surface of all blood vessels (endothelium), forms the wall of alveolar sacs in the lung and lines the body cavities (mesothelium). The primary function of simple squamous epithelia is to facilitate diffusion of gases and small molecules.
Explanation:
isme talk kro
Which statement describes a condensation reaction?
A. monomers break away when one forms a double bond monomers break away with the addition of a water molecule.
B. Two monomers combine when one adds to the double bond of another.
C. Two monomers form a new bond with the loss of a water molecule .
The statement that describes a CONDENSATION reaction is that two monomers form a new bond with the loss of a water molecule . That is option C.
CONDENSATION REACTION involves the combination of two or more molecules(monomers) of water. In reaction, a new bond is usually formed.
The characteristics of a condensation reaction includes:
formation of complex molecules (combination of two smaller monomers),water is usually given off as by product it requires a catalyst for a complete reaction to occurA reaction is called a condensation reaction because a small molecule such as water is released as a byproduct.
A typical example of a condensation reaction is the condensation of amino acids to form dipeptide. The −OH from the carboxyl group of one amino acid combines with a hydrogen atom from the amine group of the other amino acid to produce water.
Therefore, the statement that describes a CONDENSATION reaction is that two monomers form a new bond with the loss of a water molecule. That is option C
Learn more about condensation here:
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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
PLZ HELP ME WITH MY WORK
Answer:
It should be the answer D. A type of atom
Explanation:
A model is a "synthetic coordination entity that closely approaches the properties of a metal ion in a protein"
An ion is a charged atom.
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:
an atom with six protons and eight neutrons is a(n)___
a. isotope of nitrogen
b. standard carbon atom
c. isotope of carbon
d. isotope of oxygen
Answer:
standard carbon atom
Explanation:
Answer:
Explanation:
This is an isotope of carbon, more specifically, carbon-14. Carbon 14 has 6 protons, making the element carbon, and eight neutrons since 14-6 = 8.
An inorganic salt is composed of 17.6% sodium, 39.7% chromium, and 42.8% oxygen. What is the empirical formula of this salt?
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
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.
The seedlings that we planted on the newspaper cuttings or cotton wool did not grow very well at all, even though they had sunlight and water. What could they not get from the newspaper or cotton wool that plants normally get from soil?
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
Learn more: https://brainly.com/question/26032527
what’s the name of the organic molecule
Answer:
hexane
Explanation:
This is a 6- carbon hydrocarbon with no multiple bonds or any functional groups (such as -OH). Thus, the prefix 'hex' refers to the 6 carbons and 'ane' refers to the molecule being an alkane.
Naming molecules:
Number of carbons
• pentane: 5 carbons
• hexane: 6 carbons
• heptane: 7 carbons
• octane: 8 carbons
• nonane: 9 carbons
Functional groups (for 6- carbons molecules)
• Alkene (C=C): hexene
• Alcohol (-OH): hexanol
• Alkyne (C≡C): hexyne
An atom with 6 protons and 8 neutrons is an)
Answer: carbon (C)
Explanation:
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]
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.
9. a) Name salt that can be prepared by precipitation
I think its the substances that sublimes
Can compound take part in chemical reaction?
Answer:
YES!
Explanation:
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).
difference Between phenol and dettol
