Answer:
On a Plateu on a heating curve phase changes are occuring
Explanation:
The first Phase is melting during which the temrature stays the same while water melts.Other phase changes are freezing sublimation Vaourization condensation and deposition
a. For a chemistry lab final exam, a high school chemistry student was given a 1-mole sample of CaCl2 and a 1-mole sample of MgCl2 but was not told which sample was which. He was to identify the powders.
He looked up the enthalpies of formation for both of the chemicals and calculated the ΔHreaction for dissolving each powder: CaCl2 (s) Ca 2+ (aq) + 2Cl – (aq), and MgCl2 (s) Mg 2 (aq) + 2Cl – (aq). He then put each powder in a coffee-cup calorimeter and added water.
When sample A dissolved, the temperature increased by 0.74°C. When sample B dissolved, the temperature increased by 0.39°C. Which chemical was A, and which was B? Use the table of enthalpies of formation to help you. Explain your reasoning.
Ca^2+ ion is smaller than Mg^2+ ion hence it has a greater heat of formation or lattice energy.
When a crystal lattice is formed, the energy that is released if the component ions of the compound are brought together from infinity is called the lattice energy. It is the energy released when a crystal lattice is formed from its component ions.
The question lets us know that the heat released by the compounds depends on the energy released upon formation of the compound. Hence, the higher the energy released upon formation, the higher the magnitude of heat released upon dissolution of the compound.
Recall that lattice energy depends on the size of the ions. Thus, the smaller the ions, the higher the lattice energy.
Ca^2+ is smaller than Mg^2+ hence more energy is given off when CaCl2 is formed than when MgCl2 is formed.
As stated above, the greater the lattice energy, the greater the heat released when the lattice dissolves and the higher the rise in temperature.
Putting all these together, Sample A must be CaCl2 while sample B must be MgCl2.
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The compound KOH is ________. insoluble, because all compounds containing K are insoluble insoluble, because all compounds containing OH- are in soluble soluble, because all compounds containing K are soluble soluble, because all compounds containing OH- are soluble insoluble, because KOH is insoluble
Answer:
soluble because all compounds containing K are soluble
Explanation:
Most metal hydroxides are insoluble. However, alkali metal hydroxides (such as KOH and NaOH) are very soluble.
In the case of KOH, the K cation is attracted to the electronegative oxygen on water. The OH anion is capable of hydrogen bonding to the water. (Notice how OH⁻ is simply the deprotonated form of water.)
The compound KOH is soluble insoluble, because all compounds containing K are insoluble insoluble, because all compounds containing OH- are in soluble soluble, because all compounds containing K are soluble soluble, because all compounds containing OH- are soluble insoluble, because KOH is insoluble
What are alkalis?Alkalis are bases which are soluble in water. The basic alkalis are as follows:
KOHNaOHCa(OH)2Mg(OH)2 is insoluble in water.
In conclusion, KOH is a soluble base
Learn more about alkalis:
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A precipitation reaction 2. A Lewis acid-base reaction the produces a coordination complex: A Lewis acid-base reaction the produces a coordination complex 3. An oxidation-reduction reaction that is also a synthesis reaction: An oxidation-reduction reaction that is also a synthesis reaction Column B a. Pb2 (aq0 CrO42-(aq) --> PbCrO4(s) b. 2 Mg(s) O2(g) -> 2 MgO(s) c. Ag (aq) 2NH3(aq) --> [Ag(NH3)2] (aq)
Answer:
Pb2+ (aq) + CrO42-(aq) --> PbCrO4(s) - A precipitation reaction
2 Mg(s) + O2(g) -> 2 MgO(s) - An oxidation-reduction reaction that is also a synthesis reaction
Ag^+ (aq) + 2NH3(aq) --> [Ag(NH3)2]^+ (aq) - A Lewis acid-base reaction the produces a coordination complex
Explanation:
A precipitation reaction is one in which two aqueous reactants yields an insoluble product called a precipitate as shown in reaction 1 above.
In the second reaction Mg is oxidized from zero to + 2 while oxygen was reduced from zero to -2 as the MgO is formed hence the reaction is an oxidation-reduction reaction that is also a synthesis reaction.
In the third reaction, Ag^+ a Lewis acid reacts with NH3, a lewis base to yield the complex [Ag(NH3)2]^+.
¿Como pasar 254 meses a minutos?
Por favor ayudaaa!!
Le doy corona a la respuesta
Answer:
Ver las respuestas abajo.
Explanation:
Este problema se puede resolver conociendo la relacion entre horas y minutos, sabemos que:
1 hora [h] → 60 minutos [min]
De esta manera:
2 [min] = 2/60 = 0.033 [h]
15 [min] = 15/60 = 0.25 [h]
30 [min] = 30/60 = 0.5 [h]
10 [min] = 10/60 = 0.166 [h]
6 [min] = 6/60 = 0.1 [h]
20 [min] = 20/60 = 0.33 [h]
5 [min] = 5/60 = 0.0833 [h]
which chloride is a coloured solid rtp
Answer:
sodium chloride
hope that helped :)
Answer:
Chlorine is a greenish yellow gas at room temperature and atmospheric pressure. ... yielding chlorine water, and from this solution a solid hydrate of ideal ...
Oxide of nitrogen that is acidic
Answer:
Nitrogen oxides are used in the production of nitric acid, lacquers, dyes, and other chemicals. Nitrogen oxides are used in rocket fuels, in the nitrification of organic chemicals, and in the manufacture of explosives.
Explanation:
If you started with 2 moles of Nitrogen and 3 moles of Hydrogen, then you
would not have any leftover reactants. Explain which material would be
limiting since no hydrogen or nitrogen were left over?
N2 + 3H2 -> 2NH3
Answer: 0.3 moles NH3
Explanation:
list three factors that affect the rate of a chemical reaction
Answer: 1) temperature, 2) add a catalyst, and 3) concentrations
Explanation: A rise in temperature adds kinetic energy to the reactants, leading to more frequent, and energetic collisions, which will often accelerate the reaqction. A catalyst is an agent that helps the reaction move forward more quickly by offering a substrate that aids in orienting the reactants for more efficient reaction. A higher concentration increases the chances of collisons that result in products.
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
The first shell can only hold 2 electrons, but the pupil placed in 8 electrons.
The second shell can hold up to 8 electrons, but the pupil only placed in 2 electrons.
Flourine only has 9 total electrons, yet there are 10 electrons in the diagram.
Answer:
Explanation:
In the Fluorine atom there are 2 electrons in the innermost shell and 7 i the outer shell.
Sarah measures out 151 grams of SO2. How many moles is this? Express your answer to three significant figures.
Answer:
[tex]\boxed {\boxed {\sf 2.36 \ mol \ SO_2}}[/tex]
Explanation:
We are asked to convert grams to moles. We will use the molar mass and dimensional analysis to perform this conversion.
1. Molar MassThe molar mass is the mass of 1 mole of a substance. These values are found on the Periodic Table because they are equivalent to the atomic masses, but the units are grams per mole instead.
We are given a mass of sulfur dioxide (SO₂). Look up the molar masses of the individual elements.
Sulfur (S): 32.07 g/mol Oxygen (O): 15.999 g/molNotice that the formula of the compound contains a subscript. The subscript after O means there are 2 moles of oxygen in 1 mole of sulfur dioxide. We must multiply oxygen's molar mass before adding sulfur's.
O₂: 15.999 * 2 = 31.998 g/mol SO₂= 32.07 + 31.998 = 64.068 g/mol2. Convert Grams to Moles
Now we will use dimensional analysis to convert grams to moles. From the molar mass, we know there are 64.068 grams of sulfur dioxide per mole, so we can set up a ratio.
[tex]\frac {64.068 \ g \ SO_2} {1 \ mol \ SO_2}[/tex]
We are converting 151 grams to moles, so we multiply by this value.
[tex]151 \ g \ SO_2 *\frac {64.068 \ g \ SO_2} {1 \ mol \ SO_2}[/tex]
Flip the ratio so the units of grams of sulfur dioxide cancel.
[tex]151 \ g \ SO_2 *\frac {1 \ mol \ SO_2}{64.068 \ g \ SO_2}[/tex]
[tex]151 *\frac {1 \ mol \ SO_2}{64.068 }[/tex]
[tex]\frac {151}{64.068 } \ mol \ SO_2[/tex]
[tex]2.356870825 \ mol \ SO_2[/tex]
3. RoundThe original measurement of grams (151) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 6 in the thousandth place tells us to round the 5 in the hundredth up to a 6.
[tex]2.36 \ mol \ SO_2[/tex]
151 grams of sulfur dioxide is approximately 2.36 moles of sulfur dioxide.
with balanced chemical equations, show the different stages of fermentation
Answer:
formula for fermentation is: C6H12O6 → 2 C2H5OH + 2 CO.
PLS HELP!! WILL MARK BRAINLIEST! 99 POINTS!
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
what is mean by vector
Answer:
A quantity having direction as well as magnitude is called vector.
Write the empirical formula for at least four ionic compounds that could be formed from the following ions: NO3, Pb^4+, NH4, SO4
Explanation:
here's the answer to your question
double arrow just mean that it's a reversible process, and the reaction can go back and forth.
Pesticides and fertilizers are a major cause of
O air pollution
O acid rain
o the greenhouse effect
O groundwater pollution
Answer:
it means air pollution Environment. The chemicals and nutrients found in fertilizers, while beneficial for agricultural crops, can be lethal in high doses for fish, birds and other wildlife. Pesticides, designed to kill pests chemically, are also dangerous when leached into soil or groundwater supplies.
please solve this question
Answer:
b) it gets accumulated in the respiratory system which then halts or slows down the supply of oxygen to the brain hence leading to death
what is the name of this organic molecule
Answer:
C2H4 Ethylene
Explanation:
Hope it helps! :)
Describe the formation of oxygen molecule
Answer:
oxygen molecule has two oxygen atom . Each O atom share 2 electrons to form two covalent bonds out of which one is sigma bond and other is pi bond . sigma bond is formed by axial overlap 2p atomic orbitals of oxygen and pi bond is formed of lateral overlap of 2p atomic orbitals of oxygen .
what is mean by measurement
Answer:
Measurement is defined as the act of measuring or the size of something. An example of measurement means the use of a ruler to determine the length of a piece of paper. ... Extent, quality, or size as determined by measuring; dimension. A waist measurement of 32 inches.
Explanation:
The comparison o unknown quantity with known standard quantity is called measurement.
career in chemistry list ten
Answer:
Analytical Chemist
Forensics
Toxicologist
Biochemist
Chemical Engineer
Laboratory Technician
Pharmacologist
Chemical Technician
Materials Scientist
Environmental Chemist
Which type of bonds can carbon atoms form with other carbon atoms? (1 point)
O double, triple, and quadruple bonds
O single and double bonds
O double and triple bonds
O single, double, and triple bonds
Answer:
single, double, and triple bonds
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 is the order, plz answer
Answer:
C A B
Explanation:
come on, you also know this from normal water waves.
which ones are stronger (= have more energy) ? the small ones or the big ones ?
and the same applies to all waves. the bigger the waves (higher amplitude), the more energy.
Question 14 (Essay Worth 10 points) (03.05 MC) Use complete sentences to differentiate between acids and bases on the basis of touch. Give an example of each type.
Answer:
Acid is a molecule capable of donating hydrogen ion and they form aqueous solutions with a sour taste while base is a substance that accepts proton from proton donor and in aqueous solution, they have an astringent or bitter taste. Moreover, a good example for base is sodium hydrogen carbonate as baking soda or baking powder and for acid, the most common example is the acetic acid or vinegar.
Answer:
Well, for starters, bases mostly consist of soaps and cleaning products, acids consist of vinegar,lemon,and stuff like that. Most acids on the basis of touch can burn your skin or be very sour, unlike bases which are more soapy and have a cleaner touch.A good example of an acid is vinegar, which can be used for cleaning but can also be used for making foods, on the other hand. A good example of a base is dish soap. It is used for cleaning.
Explanation:
i just did the exam and got a 100
9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine. i) Students observed a visible beam of light through mixture A. Why? ii) Tincture of lodTe did not show Tyndall effect. Explain reason. ill) How can you relate particle size to Tyndall effect?
Answer:
See explanation
Explanation:
Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.
In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.
Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.
write the balanced chemical equation for the following word equation. sodium+sulphate Acidsodium sulphate +hydrogen
Answer:
2NaOH+ H2SO4 → Na2SO4 + 2H2O
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
Answer:
Sodium+sulphate=Na2SO4
Acidsodium sulphate + hydrogen=Na2SO4+H2O
What are 5 uses of nitrogen?
Answer:
nitrogen is used in the production of 1) fertilisers 2) nitric acid 3) nylon 4) dyes and 5) explosives
please give me brainliest if you can :))
How does a balanced chemical equation represent the conservation of
matter in a chemical reaction?
1. There are more atoms in the reactants than in the products.
2. The type of matter in the products is different from the type of matter in
the reactants.
3. The number of atoms of each element in the reactants equals the number
of atoms of each element in the products.
4. There are fewer atoms in the reactants than in the products
Answer:
The correct answer would be 3. The number of atoms of each element in the reactants equals the number of atoms of each element in the products.
Explanation:
The law of conservation of matter states that energy cannot be created or destroyed, only transfered. Thus, option 3 is correct.
16. The valency of sodium is +1 and that of chlorine is -1, why?
Answer:
It because ,sodium is a metal and chlorine is a non metal
Define force and speed
Force = The external energy that changes or tends to change the state of any body or object is called force.
Speed = The rate of distance is called speed.
Answer:
Force is a push or pull which changes or tend to change the position of a body.
The rate of change its position with time or magnitude is called speed.
