19. place moth balls in the closet and observe after several days.
20. whenever wax or a candle burns it turns from solid to liquid but again at room temperature it turns to solid
21. evaporation, condensation, precipitation
22. it produces new substances
23. vinegar Bubbles when baking soda is added
24. steam
As a person BAC level increase it becomes difficult for them to judge their vehicle distances and speed
Answer:
TRUE
Explanation:
The blood alcohol content is also known as the blood alcohol level or the blood alcohol concentration. It is defined as the measurement of the alcohol intoxication in the body and is used for the legal or the medical purposes.
When the BAC increases in the person's body, the person started to loose clear vision, loss of short term memory, poor muscle coordination, impaired perception and face difficulty in concentrating. Thus it becomes very difficult for a person to drive a car or ride a bike whose BAC has increased.
The driver cannot properly judge the distances between the vehicle and the speed of the vehicle.
Hence the answer is TRUE.
22.5 ml of a 0.200 m HBr solution was added to a 50.00 ml sample of 0.250 m sodium benzoate (NaC7H5O2). Calculate the pH. Benzoic acid has a Ka 6.30 x 10-5.
In this problem, we need to find the pH of a buffer (pH = 4.45) that is produced by the reaction of strong acids as HBr that reacts with weak bases as NaC₇H₅O₂ producing its weak acid and a salt, as follows:
HBr + NaC₇H₅O₂ → HC₇H₅O₂ + NaBr
If in the reaction, the limiting reactant is the strong acid, we will produce a buffer (The aqueous mixture of a weak acid and its strong base).
Using Henderson-Hasselbalch equation, we can find the pH of this buffer:
[tex]pH = pKa + log \frac{[NaC_7H_5O_2]}{[HC_7H_5O_2]}[/tex]
Where:
pKa is -log Ka = 4.20
[] could be taken as the moles of each species
After the reaction, the moles of HBr = Moles of HC₇H₅O₂ and the remaining moles of NaC₇H₅O₂ = Initial moles of NaC₇H₅O₂ - Moles of HBr.
Moles HBr:
22.5mL = 0.0225L * (0.200mol/L) = 4.5x10⁻³ moles HBr
Moles NaC₇H₅O₂:
50.0mL = 0.0500L * (0.250mol/L) = 0.0125 moles NaC₇H₅O₂
That means the moles after the reaction of the species of the buffer are:
Moles HC₇H₅O₂ = Moles HBr = 4.5x10⁻³ moles
Moles NaC₇H₅O₂ = 0.0125 moles - 4.5x10⁻³ moles = 8.0x10⁻³ moles
Replacing in H-H equation:
[tex]pH = 4.20+ log \frac{[8.0x10^{-3}]}{[4.5x10^{-3}]}[/tex]
pH = 4.45
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Which of the following is not a result of surface tension in water?
a. water has an unusually low vapor pressure
b. drops tend to become spherical
c. surface area is maximized
d. surface appears to have a “skin”
The option which isn't a result of surface tension in water is: c. surface area is maximized.
Water can be defined as a liquid molecule that comprises the chemical element hydrogen and oxygen in the ratio of two to one (2:1).
Surface tension can be defined as a property of liquid such as water, which makes its surface to resist an external force due to the cohesive nature of its molecules.
This ultimately implies that, the surface tension of a liquid is mainly as a result of the cohesive forces existing between its molecules.
Generally, the surface tension of water is typically higher than the surface tension of most liquids.
Due to the effect of surface tension in water;
Water has an unusually low vapor pressure due to the hydrogen bond between its molecules.Drops of liquids such as water tend to become spherical.The surface of a liquid such as water appears to have a “skin”Additionally, the surface tension of a liquid such as water can be described as an inward force which tends to minimize its surface area rather than maximize its surface area.
In conclusion, surface tension in water doesn't maximize its surface area.
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explain the importance of measurement in our daily life
Questions: Answer on the following slide.
1. What is needed from adults when conducting experiments at home?
2. Why are chemicals so dangerous?
3. What should always be followed when conducting experiments?
4. What is science?
If you start with 4.5 moles of aluminum and 6.5 moles of copper chloride to make aluminum chloride and copper, what is the limiting reagent?
2Al + 3CuCl -> 2AlCl3 + 3Cu
Answer:
The limiting reagent is CuCl
Explanation:
The initial number of moles of aluminum, Al = 4.5 moles
The number of moles of copper, Cu = 6.5 moles
The given chemical reaction is presented as follows;
2Al + 3CuCl → 2AlCl₃ + 3Cu
Therefore, we have, 2 moles of aluminum combine with 3 moles of CuCl produces 2 moles of AlCl₃ and 3 moles of Cu
1 mole of Al will combine with (3/2) moles of CuCl,
Therefore, 4.5 moles of Al will combine with (4.5 × (3/2) = 6.75) 6.75 moles of CuCl
Given that the number of moles of CuCl present is only 6.5 moles which is less than the 6.75 moles required to combine with the 4.5 moles, the 6.5 moles of CuCl limits the amount of AlCl₃ and Cu produced, and therefore the CuCl is the limiting reagent.
Convert 25 yards to inches
using the method of dimensional analysis
Answer:
Explanation:
25 yard [3 feet / 1 yard] [12 inches / 1 foot] = 25 * 3 * 12 = 900 inches in 25 yards.
Always put the unit you are going to on top and the unit you are coming from on the bottom.
So in this example, you want to going to feet to start with. That's on top. Yards are on the bottom of the first bracket. In second bracket feet are on the bottom, inches are what you are going to on the top.
can you solve this science question ⁉️
Answer:
chemical reaction between those a b c it's a reaction which occurs when heating
PLZ HELP There are two main ways that organisms reproduce, or make more Individuals of their own kind. Which of the following is true of these two types of reproduction?
A. In one way, two parents are involved. In the other, there is only one parent
B. In reproduction that involves only one parent, the offspring are different from the parent. In reproduction that involves two parents, the offspring receive exact copies of the parents' DNA.
C. In both ways, offspring share characteristics with their parents but are not exactly the same. O
D. In both ways, all offspring are identical to each other but maji different from their parents.
Answer:
A
Explanation:
Two parents are involved in Sexual Reproduction but only one is involved in Asexual Reproduction.
Convert the following moles to grams :)
1. 2.4 moles sulfur
2. 1.5 moles BeI2
3. 7.5 moles C6H12O6
Answer:
3
Explanation:
sky is high and I am good.
what is precipitating ???
anyone please tell me how to delete an I'd
Explanation:
Desposition of solid matter in a solution
13. Water is a polar compound because it exhibits _______
charges.
O A. negative
O B. positive
O C. opposite
D. neutral
Answer:
Opposite.
Water exhibits negative charge near hydrogen, positive near oxygen.
This is why it is OPPOSITE.
Let me know if this helps!
Water is a polar compound because it exhibits opposite charges. Therefore, option C is correct.
What is polar compound ?The term polar compound is defined as the compound with distinct regions of positive and negative charge, as a result of bonding with atoms such as nitrogen, oxygen, or sulfur.
Water is a polar compound because the covalent bonds between hydrogen and oxygen in the water molecule are polar in nature. Any molecule with lone pairs of electrons around the central atom is polar compound.
In water there are two atoms are present that are oxygen and hydrogen. Hydrogen has positive charge while oxygen has negative charge,
Thus, Water is a polar compound because it exhibits opposite charges, option C is correct.
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PLZ HELP ME WITH MY WORK
What is a compound?
A substance that is made from two different metals
B. A substance that cannot be broken into simpler substances
C. A substance that is made using a chemical reaction
D. A substance that can be separated by physical means
Answer:
C.
Explanation:
Answer A is incorrect because a compound doesn't have to be made with only metals.
Answer B is incorrect because that is actually the definition of a pure element.
Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.
Answer D is incorrect because compounds cannot be separated by physical means.
Hope this helps :D
What is the name for the compound li2so4
Answer:
Explanation:
Lithium Sulphate
Answer:
Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid.
Which of the following apply to organic compounds. Select all that apply. Organic compounds cannot be synthesized. Organic compounds contain carbon. All organic compounds are products of living things. Organic compounds can be synthesized. All compounds that contain carbon are organic.
Answer:
Organic Compounds CAN BE synthesized
Organic Compounds contain Carbon
how would you detect sulphur in organic compounds
Answer:
sodium fusion is changed to sodium sulphide if sulphur is present in the compound
please answer this questions soon
i will mark him or her brillient
Answer:
1)Or
d.Sublimation
2)
b.iodine is the solute and alcohol is solvent
3)
a.compostion of solute
Answer:
1) a) centrifugation
OR
b) sublimation
2) a) iodine is the solute and alcohol is solvent
3) a) concentration of soLute
Vitamin C is a water-soluble vitamin, so your body doesn't store it. You have to get the required amount from your diet (citrus fruits are a great source!), or you could take a daily vitamin C supplement pill. Vitamin C is ascorbic acid, so to determine how much vitamin C (acid) has been placed in each pill, you could do an acid-base titration. One vitamin C pill was dissolved in water and titrated to an endpoint by 16.00 mL of a 0.447 M solution of NaOH. How many grams of ascorbic acid were there in the pill? (MW of ascorbic acid is 176.1 /mol). Explain and show your work.
Answer:
1.26 g
Explanation:
Number of moles of ascorbic acid = concentration × volume
Concentration = 0.447 M
Volume = 16.00 mL
Number of moles = 0.447 × 16/1000
Number of moles = 7.152 × 10^-3 moles
Number of moles= mass/molar mass
Molar mass of ascorbic acid = 176.1 g/mol
Mass = 7.152 × 10^-3 moles × 176.1 g/mol
Mass = 1.26 g
how do i know if a salt is insouble or soluble?
[preparations of salts]
Answer:
by the expirement:
In which mix salt with water
If we shake the branches of the tree the fruits fall.why?
Answer:
When we shake the branch of a tree the tree possesses a state of motion whereas the fruits and leaves tend to remain in state of rest. Due to this inertia of rest the fruits and leaves get detached from the branch and because of gravity it falls down.
Explanation:
so it's because of the gravity .
According to the law of conservation of energy, what will most likely happen in a closed system?
Answer:
It is right or wrong I cannot say if it is wrong forgive me.
Answer:
The energy in the system will likely be exchanged, but the matter will not be exchanged.
Explanation:
According to the first law of thermodynamics, also known as Law of Conservation of Energy, energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another. The law of conservation of mass also states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change.
which option correctly shows the bond angle of a linear molecule?
a. 109.5 degrees
b. 90 degrees
c. 120 degrees
d. 180 degrees
Taking into account the definition of molecular geometry, the correct option is option d.: the bond angle of a linear molecule is 180 degrees.
In first place, molecular geometry or molecular structure is the spatial distribution of atoms around a central atom. Atoms represent regions where there is a high electron density, and are therefore considered electronic groups, regardless of the bonds they form.
That is, molecular geometry is the three-dimensional arrangement of the atoms that make up a molecule.
The molecular geometry of an element characterizes some of its physical or chemical properties, such as boiling point, viscosity, and density.
Linear molecules are molecules of the AB₂ type in which the central atom does not have lone pairs. To avoid repulsions between the binding pairs, arrange the B groups as far apart as possible. For that they must oppose each other 180 °.
In summary, linear molecular geometry describes the arrangement of different atoms with 180º bonds.
So, the correct option is option d.: the bond angle of a linear molecule is 180 degrees.
Learn more about molecular geometry with this example:
https://brainly.com/question/11298860?referrer=searchResultshttps://brainly.com/question/14203216?referrer=searchResultshttps://brainly.com/question/9965422?referrer=searchResultshii pls help me to balance the equation thanksss
Explanation:
2KCLO3 (s) = 2KCl (s) + 3O2 (g)
Identify what type of reaction is taking place:
CH3CH3 + Br2 -> CH3Br + HBr
A. Addition
B. Fermentation
C. Substitution
D. Elimination
what is the product of SO2+H2O.
Answer:
H2O + SO2 → H2SO3
Explanation:
H2O + SO2 → H2SO3
Answer:
l think this is the answer .
steel cranes can carry heavy steel beams thousands of feet high
Answer:
yes they were made to carry thousands of lb high up
Chemistry!! Help me! And explain step by step!
1st part is ure answer --> 2M
Given mass -> 58 grams
mass of NaCl -> 58.44 approx -> 58 any
moles given-> 1 moles
[tex]Molarity = \frac{moles}{vol \: in \: lts} [/tex]
[tex]Molarity = \frac{1}{0.5} = \frac{10}{5} \\Molarity = 2M[/tex]
what more accurate model of the atom emerged from Albert Einstein's contributions and quantum mechanics
Answer:
Einstein also in 1905 mathematically proved the existence of atoms, and thus helped revolutionize all the sciences through the use of statistics and probability. Atomic theory says that any liquid is made up of molecules (invisible in 1905)
Explanation:
Answer:
The discoveries of Albert Einstein led to development in the understanding of the atom through the study of quantum mechanics and the electron cloud. In this model, there is still a nucleus with protons and neutrons. But unlike the Bohr model, the electrons exist in a cloud outside the nucleus, much like the fruit around the pit of a peach.
Explanation:
how many protons electrons and neutrons are present in the following atoms
Answer:the element is potassium
the proton and electron is 19 and the nuetron is 19
Explanation:
Answer:
The atomic number gives the number of protons 19
p = 19
The atomic mass is the sum of the protons and neutrons
p+n = 39 p = 19
Put p into the equation and solve for n the neutrons
19+n = 39
Subtract 19 from both sides
19-19+n = 39-19
n = 20
The number of electons equal the number of protons in a neutral atom. The positive charge equal to the negative charge. The negative charge is the number of electons. This ion has a charge of +1. So solve for the negative charge.
-19+1 = -18
The negative charge is -18 so
e = 18
3. What would be the freezing point for a 5.7 molal aqueous sucrose (C12H22O) solution? The freezing
point depression constant for water = 1.86°C/m. Show your work.
Answer:
- 10.6° C
Explanation:
Given that,
In the aqueous sucrose solution,
Molality of the solution (m) = 5.7
Freezing point constant (K) = 1.86
To find,
The freezing point of the solution = ?
Method:
To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.
In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,
ΔT(change in temperature) = i * m * K (putting the given values)
= 1 * 5.7 * 1.86
= 10.6° C
Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.