Answer:
B
Explanation:
Pure water always has equal concentrations of hydrogen and hydroxide ions.
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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2. Low-density polyethylene, used to make plastic films, is
made by the radical polymerization of ethene, and is one of
the hardest plastics to recycle. It gets its name
A. from the process by which it's polymerized.
B. because of the way the chains pack like spaghetti, close
and tight.
C. from the spaces left between chains when the polymer is
formed.
D. because it's strong but flexible.
Answer:
from the spaces left between chains when the polymer is
formed.
Explanation:
Polyethylene polymer may be of high or low density. Whether the polymer is of high or low density depends on the arrangement of the polymer chains.
If the polymer chains are close together such that the resultant polymer is crystalline with chains packed closely, we have high density polyethylene.
On the other hand if the chains are not close together and there are spaces left between chains when the polymer is formed, then we have low density polyethylene.
Hence, low density polyethylene gets its name from the spaces left between chains when the polymer is formed.
Answer: it gets its name (from the process by which it's polymerized). Therefore the correct option is A.
Explanation:
Polyethylene is a type of plastic which is made by the polymerization of its monomers (ethene). The most common monomers are derived from petrochemicals. The monomers simply join together to form the polymers which has the same empirical formula as the monomer, but is of a higher molecular mass.
There are two main types of polyethylene, these include:
--> Low density polyethylene: when ethene is subject to a high temperature of about 250°C and pressure above 1500atm, together with traces of oxygen ( as an initiator), it polymerizes to polyethylene. The polyethylene obtained by the above method is called a low density polyethylene. It has the most long- and short-chain branching of any form of polyethylene, resulting in its lower density. Therefore its name is gotten from the process by which it's polymerized
--> High density polyethylene: this is prepared at a lower temperature and pressure by using catalysts.
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.
When a solid dissolves in a liquid, it is termed
Answer:
Soluble
Explanation:
hope this helps
hii pls help me to balance the equation thanksss
Answer:
3Fe(s)+2O2(g)---->Fe3O4
this way you will have 3irons on both sides and 4 oxygens.
I hope this helps
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\red{\sf{3Fe(s) + 2O_{2}(g)\dashrightarrow Fe_{3}O_{4}(s)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
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.
difference Between phenol and dettol
Blood test can be used to check a person's blood glucose and hormone levels. The tabular column given below shows the result of two blood tests carried out on three people to check their blood glucose levels. Person 1 is healthy.
A:- Compare the glucose levels of person 1 with the glucose levels of person 2 after fasting for 12 hours.
B:- Compare the glucose levels of person 3 with the glucose levels of person 1, 2 hours after drinking 75g glucose.
C:- Person 3 cannot be produce the hormone that control blood glucose levels. State the hormone that person 3 cannot produce.
( THE ORDER OF THE PHOTO IS:- person 1, and person 2, and person 3)
Pls it is urgent
Answer:
Explanation:
1) person 2 had a slightly higher blood glucose level than person 1 after fasting 12 hrs (0.2mmols)
2) person 3 has a much higher blood glucose level than person 1 after taking glucose (5.6mmols)
3) insulin
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
4.1 shows a plant cell. g For Examiner's Use n. C D Fig. 4.1 (i) Name the type of plant cell shown in Fig. 4.1. [1]
Answer:
palisade cell due to presence of chloroplasts
8 - Escriba la fórmula del siguiente compuesto nitrogenado
Dietil benza amida
Answer:
Ver explanación e imagen adjunta.
Explanation:
El compuesto se conoce generalmente como N, N-dietilbenzamida.
Es una amida porque tiene la fórmula general RCONR.
La molécula se llama N, N-dietil benzamida porque los dos grupos etilo están unidos al átomo de nitrógeno como se muestra en la molécula.
How many Sodium (NA) Atoms are in Calcium Oxide
Answer:
2 Na atoms
Explanation:
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)
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
When a leaf of fresh sage or mint is rubbed ,the fragrance is
immediately obvious. Write a theoretical explanation for this observation
Answer: Volatile compounds present in the fresh sage leaf or mint leaf evaporate on rubbing.
Explanation:
When fresh sage or mint is rubbed on the skin or any other surface the volatile chemicals associated with the integral structure of the plant part get evaporated in the surrounding air and the vapors can be detected by the olfactory receptors present in the nose. These receptors take the smell or fragrance stimulus and generate impulses or signals which goes to brain and brain interprets the smell or fragrance.
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
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=
$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=x\times molar\:mass}$
$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=0.25\times 40=10}$
$\space$
$\sf\underline{\underline{ ⚘ Hence,amount\:of\:NaOH=10kg}}$
_______________________________
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
Describe the principle and process for the manufractured of sulphuric acid witha a well labeled diagram by contact process.
The steps involved in the manufacture of sulphuric acid by contact process:
(1) Sulphur (or iron pyrites) are burnt in air to form sulphur dioxide.
S+O2→SO24FeS2+11O2→2Fe2O3+8SO2
(2) Catalytic oxidation of sulphur dioxide to sulphur trioxide.
2SO2+O2V2O52SO3ΔrHo=−196.6kJ
The reaction is reversible and exothermic.
(3) Sulphur trioxide is dissolved in 98% sulphuric acid to form oleum (fuming sulphuric acid).
SO3+H2SO4→H2S2O7
(4) Oleum is diluted with water to form sulphuric acid of desired concentration.
H2S2O7+H2O→2H2SO4
and
Manufacture of H2SO4 by contact process involves three steps:
1. Burning of sulphur in air to generate SO2.
2. Conversion of SO2 to SO3 by oxidation with air in the presence of
Please help :)
A chocolate chip cookie recipe calls for 0.050 moles of baking soda (NaHCO3). How many grams should the chef mass out?
According to the mole concept, 4.2 g of baking soda should be weighed out.
What is mole concept?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Baking soda has molar mass of 84 g /mole, thus mass is calculated using number of moles formula which is mass= molar mass×number of moles, which is mass=84×0.050=4.2 g.
Thus,4.2 g of baking soda should be weighed out by chef.
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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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Isotopes are atoms that have the same mass number, but different numbers.
atomic. True or false
Answer: Im not sure but I think it is false.
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]
state the modern periodic law
Answer:
The modern periodic law states that the physical and chemical properties of the elements are the periodic function of the atomic numbers and electronic configurations. ... This repetition occurs if the arrangement of the elements is in order of their increasing atomic numbers.
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?
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
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9. a) Name salt that can be prepared by precipitation
I think its the substances that sublimes
An inorganic salt is composed of 17.6% sodium, 39.7% chromium, and 42.8% oxygen. What is the empirical formula of this salt?
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
While driving her car on a hot sunny day, a woman was struck in the back of the neck by the dough from an exploding can of Pillsbury biscuits. From the sound it made and the feeling of warm sticky dough on her neck, she thought she had been hit by a bullet! Describe the likely conditions that caused this to happen. Be sure to explain AT THE MICRO scale how the particles were affected.
Answer:
The dough is made from flour sugar, baking soda, sometimes yeast. The sugar is converted into gaseous products including carbon dioxide, CO₂ and alcohols. As more gases are produced, the pressure increases, and according to Charles's law, as the temperature on a sunny day is higher than on a cool day, the pressure of the gases increases further, to the point that the can containing the biscuits can not hold the pressure, leading to an explosion
Explanation:
