Answer:
second (S) is the SI unit of time.
Answer:
second
Explanation:
the gap between any two intervals is called time
time can be measured in hour,minute,second
but second is the SI unit of time
Which of these solutions is acidic?
Answer:
Option a is a solution acidic ([OH⁻] = 7.0x10⁻⁹ M).
Explanation:
To know if a solution is acidic we need to calculate the pH and it must be lower than 7. A value of pH equal to 7 is a neutral solution and a solution with a pH value higher than 7 is a basic solution.
a. For the [OH⁻] = 7.0x10⁻⁹ M we have:
[tex] pOH = -log[OH^{-}] = -log(7.0 \cdot 10^{-9}) = 8.15 [/tex]
Now, the pH is:
[tex] pH + pOH = 14 [/tex]
[tex] pH = 14 - pOH = 14 - 8.15 = 5.85 [/tex]
This solution is acidic (pH < 7)
b. [H₃O⁺] = 8.5x10⁻⁸ M
[tex] pH = -log(8.5 \cdot 10^{-8}) = 7.07 [/tex]
This is not an acidic solution. Is a neutral one (pH around to 7).
c. [OH⁻] = 2.5x10⁻⁶ M
[tex] pOH = -log[OH^{-}] = -log(2.5 \cdot 10^{-6}) = 5.60 [/tex]
Then, the pH is:
[tex]pH = 14 - pOH = 14 - 5.60 = 8.40[/tex]
Hence, this is not an acidic solution. It is basic (pH > 7).
Therefore, option a is a solution acidic ([OH⁻] = 7.0x10⁻⁹ M).
I hope it helps you!
The number of joules required to heat one gram of a substance one degree Celsius is _____.
endothermic
temperature
exothermic
specific heat capacity
what is the product of SO2+H2O.
Answer:
H2O + SO2 → H2SO3
Explanation:
H2O + SO2 → H2SO3
Answer:
l think this is the answer .
why is the Dna molecule able to open up and close?
Answer:
The breaking of the hydrogen bonds due to the force relieves the torsional stress stored in a double helix. As a result, the nucleotide strands rotate more freely about the axis of a helix and start unwinding. ... The DNA unzipping and the DNA unwinding result in a structural transformation from dsDNA to ssDNA.
Differentiate between emperical and
molecular formula. Give an example of
a substance having different emperical
and molecular formula
Answer:
Here’s an example:
CH (methylene) is the empirical formula.
C2H2 is a molecular formula. It is a gas called Ethyne.
C8H8 is an oily liquid called Styrene. It is also a molecular formula.
Now compare: even though the empirical formula for these compounds is the same, they have different molecular formulas and different properties.
Explanation:
Some background information:
The empirical formula is the formula with the lowest whole number ratio of an element in a compound. A molecular formula is the chemical formula of a (molecular) compound. The molecular formula gives us the exact number of atoms or moles in that compound.
I have attached pictures for a better understanding of the empirical formula.
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.
A new stable element with an atomic number of 120 and an atomic mass of 246 is created in a particle accelerator. Enough of this element is created to determine that it combines with chlorine in a 1:2 ratio. Element 120 should be placed in the same group as _____ on the periodic table.
Answer:
Be,Mg,Ra etc
Explanation:
It should be palced in group 2A because as it reacts with chlorine in ratio of 1:2 . It's valancy is 2 and is metal as it react with non metal donating two electrons .
one more thing it fits there orderly
How can the percentage of air be determined
Answer:
The composition of air can be determined by an experiment which includes passing a known volume of air, measured at a known temperature and pressure, over sufficient amount heated copper granules/powder, and measuring the volume gas remaining after the gas cools down to the temperature at which the first measurement was taken
Oxygen reacts with copper according to the following chemical reaction
2Cu (s) + O₂ (g) → 2CuO (s)
Cupper does not react with the other constituents of air
Whereby the initial volume of air was 100 cm³, we have;
Percentage of oxygen in air = 100 - The final volume reading of the container initially holding the air
When done using am appropriate experimental setup, the percentage of gases remaining equals 79% to 80%, therefore, the percentage composition of oxygen in air is between 20 and 21 percent
Explanation:
****URGENT****
I need help!!!
the answers are there, i need someone to explain please!
Explanation:
your answer was correct
Type the correct answer in the box. Express your answer to two significant figures. You are performing a reaction with 1.7 moles of hydroiodic acid and 3.43 moles of zinc bromide: 2HI + ZnBr2 → 2HBr + ZnI2. How many moles of zinc iodide can be made? The theoretical yield is moles of zinc iodide.
Answer:
1.34 34343 he did
Explanation:
i did the test
Answer:
0.85
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]
What is an atomic mass unti
Explanation:
a unit of mass used to express atomic and molecular weights, equal to one twelfth of the mass of an atom of carbon-12.
Answer:
Atomic Mass Unit is also called Dalton. It is used to express atomic and molecular weight. It is defined as 1/12 of the mass of an unbound neutral atom of carbon.
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
Potassium impart purple colour but beryllium do not impart any colour to the flame.Why?
Answer:
The electrons in beryllium and magnesium are too strongly bound to get excited by flame. Hence, these elements do not impart any color.Which of the following describes scientists?
О
A. People with only one perspective
B. People with similar personalities
C. People from different backgrounds
D. People with perfect understanding of science
Which elements on the periodic table are the least reactive? (1 point)
o the group with helium at the top
the group with hydrogen at the top
the group with carbon at the top
the group with fluorine at the top
Answer:
the group with helium at the top
Explanation:
I just took it
Small quantities of spilled acids can be made safe with *
1 point
o gasoline.
alcohol.
water.
sodium bicarbonate solution.
Answer:
sodium bicarbonate solution
Identify the correct mole ratio for each substance.
Sodium chloride (NaCl)
Na:Cl = 1: _
Ammonium nitrate(NH.NO3)
H:0 = 4: _
Answer:
The mole ratio of H : O in ammonium nitrate is 4 : 3.
Explanation:
We are given a compound named ammonium nitrate having formula
There are 3 elements in this compound which are nitrogen, hydrogen and oxygen.
To calculate the mole ratio, we write the ratio of their subscripts. For this compound,
A sample of gas occupies 1.2 L at 12.0oC. Assuming pressure remains the same, what would be the volume (in L) of this gas at 67oC?
A.
1.4
B.
1.0
C.
0.2
D.
5.0
E.
6.7
Answer:
e.
6.7
hope it help
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name some examples of chemical solutions and maybe give a clear explanation as to what chemical solutions are
Answer:
Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. ... In our example of salt water, the solute is the salt. Solvent: this is the substance that makes up the majority of the solution. This is the part where the solute is dissolved.
Explanation:
I hope they should be right answer
Which of the following is a scientific question you could ask about the game
of basketball?
A. Do you enjoy basketball more than volleyball?
B. Which team is this year's best?
C. Which player should be traded to another team?
D. Do teams that practice more win more games?
SUBMIT
The scientific question related to the game of basketball is option D: "Do teams that practice more win more games?"
This question is scientific because it explores a cause-and-effect relationship between practice and game outcomes. It can be investigated through empirical observation and data analysis.
To answer this question, researchers could collect data on the practice hours of different basketball teams and compare them to their corresponding game performance. Statistical analysis could be used to determine if there is a correlation between practice time and winning percentage or other performance metrics.
By examining a large sample of teams over an extended period, researchers could draw conclusions about the impact of practice on game outcomes. This scientific inquiry would contribute to the understanding of the factors that influence team success in basketball and could potentially inform training strategies and coaching techniques.
For more question on basketball
https://brainly.com/question/29505871
#SPJ8
Using these metal ion/metal standard reduction potentials calculate cell potential for Cu2+(aq) + Cd(s) →Cd2+(aq)+ Cu(s) Cu2+(aq)|Cu(s) + 0.34 VNi2+(aq)|Ni(s) -0.25 Cd2+(aq)/Cd(s) -0.4V
Solution :
Cd(s) ----------------------> [tex]Cd^{+2}[/tex] (aq) + 2[tex]e^-[/tex] , [tex]E_0[/tex] = 0.34 v
[tex]Cu^{+2}[/tex] (aq) + 2[tex]e^-[/tex] ------------> Cu (s) , [tex]E_0[/tex] = -0.04 v
----------------------------------------------------------------------------------------------
Cd(s) + [tex]Cu^{+2}[/tex] (aq) -------------> [tex]Cd^{+2}[/tex] (aq) + Cu (s) , [tex]E_0[/tex] = 0.30 v
The cell potential is defined as the measure of [tex]\text{ potential difference }[/tex] between the [tex]\text{two half cells}[/tex] of an electrochemical cell.
can you solve this science question ⁉️
Answer:
chemical reaction between those a b c it's a reaction which occurs when heating
hii pls help me to balance the equation thanksss
Explanation:
2KCLO3 (s) = 2KCl (s) + 3O2 (g)
For the reaction 2HNO3 + Mg(OH)2 + Mg(NO3)2 + 2H20, how many
grams of magnesium nitrate are produced from 3.54 mol of nitric
acid, HNO3?
O a. 220
O b. 263
O c. 1050
O d. 175
Answer:
B
Explanation:
Some species form social groups only with members of the same gender. For example, elephants form groups with
only females and their offspring. Once the male offspring reach a certain age, they leave the group and become
solitary.
Which is a benefit of this type of social group structure?
Explanation:
For example, elephants form groups with only females and their offspring. Once the male offspring reach a certain age, they leave the group and become solitary. Which is a benefit of this type of social group structure? A:Females do not have to compete for a mate.
Suppose you had a valuable collection of small diamonds, which you kept safe from the thieves by mixing them with white sugar crystals. You store the mixture in a jar labeled 'sugar'. Now you want to sell the diamonds. Describe how you would separate all the diamonds from the sugar.
Answer:
Pour the sugar/diamond mixture into a container of water and stir until the sugar is dissolved completely. Then strain the mixture and wash the diamonds with water.
Answer:
Stir with a large enough volume of cold water to dissolve all the sugar. Filter to leave the diamonds on the filter paper. Wash on the filter paper with more water to remove any last traces of sugar solution. Allow to dry.
Do plants need soil to grow
Answer:
Not all plants do need soil to grow
Explanation:
Not all plants need soil to grow. Some just do better in soil compared to other growing mediums. What plants need are minerals and nutrients, such as nitrogen, potassium, and phosphorous. Soil is an effective way of delivering those nutrients cost-effectively. You can also use alternative delivery systems like hydroponics, aeroponics, and aquaponics to achieve the desired effect. However, these are only suitable for growing shallow-rooted plants. Plants with deep roots will always need soil, as will larger plants with spreading roots.
3. A typical peanut butter and jelly sandwich contains 360 kcal, of which 160
kcal comes from fat. Given 1 kcal = 4.2 kJ, how many J of fat would there be
in one PB&J sandwich?
Explanation:
here's the answer to your question
Which statement describes the law of conservation of energy?
All systems will exchange matter and energy with their surroundings.
All systems can exchange energy, but not matter, with their surroundings.
Energy cannot be created nor destroyed, but it changes from one form to another.
Energy is destroyed in most chemical reactions when new products are formed.
Answer:
All systems will exchange matter and energy with their surroundings.
Explanation:
Answer:c
Explanation:
Are you ready kids?
Aye, aye Captain.
I can't hear you!
AYE, AYE CAPTAIN!
Oooooooooh.
Who lives in a pineapple under the sea?
Spongebob squarepants!
Absorbent and yellow and porous is he?
Spongebob squarepants!
If nautical nonsense be something you wish!
Spongebob squarepants!
Then drop on the deck and flop like a fish!
Spongebob squarepants!
Ready?
Spongebob squarepants.
Spongebob squarepants.
Spongebob squarepants.
Spongebob squarepants.
Spongebob-squarepants.
