Answer:
The correct answer is - valid.
Explanation:
In this case, there is consistency in the results measures in the experiment which makes this method reliable. The consistency of a measure is referred to the reliability.
It is also given that the level of contamination of individual containers as per the average parameter of the contamination of large containers which makes this method not valid as the measurement method is how correctly it measures the true value of the parameter.
Thus, the correct answer is - method is reliable, but not valid.
plz help as soon as you can
Oil of Vitriol is a substance that humankind has used for thousands of years! Today the substance is known by its scientific name sulfuric acid and has the molecular formula H2SO4. What is the molar mass of H2SO4?
Question 2 options:
49.067 g/mol
73.29 g/mol
98.08 g/mol
148.72 g/mol
Answer:
98.08 g/mol
Explanation:
Hope this helps.
20 g of Allg is dissolved in water to produce a solution with a concentration of 2.007M. What is the volume of this solution in milliliters?
Answer:
369 ml
Explanation:
Mass of Aluminium (Al) = 20 g
Molar concentration = 2.007M
Molar concentration = Number of moles / Volume
The relationship between mass and number of moles;
Number of moles = Mass / Molar mass
Number of moles = 20 / 27 = 0.741 mol
2.007 = 0.741 / Volume
Volume = 0.741 / 2.007 = 0.369 L
converting to millilitres by multiplying by 1000
Volume = 0.369 * 1000 = 369 ml
35.2 J of heat is
applied to 16.0 g
of a substance.
Temp rises by 7.2
K. Specific Heat?
The specific heat : c = 0.306 J/g K
Further explanationGiven
Heat = 35.2 J
Mass = 16 g
Temperature difference : 7.2 K =
Required
The specific heat
Solution
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Input the value :
c = Q / m.∆T
c = 35.2 / 16 x 7.2
c = 0.306 J/g K
The diagram shows the electron configuration around the chlorine nucleus. Chlorine has 17 protons.
CI
Which of the following correctly completes the statement?
Chlorine has valence electrons, and the effective nuclear charge, Zett, for the chlorine atom shown is
O A. 7,7+
OB. 7,7-
O C. 10,7-
D. 17, 7+
Answer: A. [tex]7,+7[/tex]
Explanation:
Valence electrons are the number of electrons constituting the outermost shell of an atom. It is also defined as the electrons that take part in the formation of a chemical bond.
The atomic number of chlorine is 17 as it has 17 protons and the electronic configuration will be 2,8,7. Thus the electrons present in the outermost shell are 7 and hence the valence electrons are 7.
Effective nuclear charge is the net positive charge experienced by valence electrons. It is calculated by: Zeff = Z – S
where Z = atomic number , S = number of shielding electrons.
Thus for Chlorine , [tex]Z_{eff}=17-10=7[/tex]
Sam noticed on a climate map that most of the areas with high rainfall and a tropical climate were located in one region. Why are all the rainy, tropical areas found at a similar latitude? Describe the factors that influence the climate in this location.
Answer:
Okay here's the answer ↓
Step-by-step explanation:
Tropical climate is one of the five major climate groups in the Köppen climate classification. Tropical climates are characterized by monthly average temperatures of 18 ℃ (64.4 ℉) or higher year-round and feature hot temperatures. Annual precipitation is often abundant in tropical climates, and shows a seasonal rhythm to varying degrees. There are normally only two seasons in tropical climates, a wet season and a dry season. The annual temperature range in tropical climates is normally very small. Sunlight is intense because they are receiving direct sunlight.
1.A cup of coffee with cream and sugar is a mixture (true or false)
2.give two examples of mixtures you see everyday in life
3.Look at the pictures of methods of separating a mixture and write down the correct names under each picture
(pictures are attached)
Can someone explain how it is 1?
Explanation:
You have 112 g of Fe.
The atomic mass of Fe is 56 g/mol
112g Fe/ 56g/mol = 2 mol Fe <---- you have to convert to moles of iron(iii) sulfate
From the balanced equation, you get that 2 moles of Fe react to produce 1 mole of Fe2(SO4)3
So, to convert:
2 mol Fe* (1 mol Fe2(SO4)3 / 2 mol Fe) = 1 mol Fe2(SO4)3
moles of Fe cancel and the answer is 1 mole of iron(iii) sulfate.
Which of the following describes how the mid Atlantic ridge formed on earth at a divergent plate boundary.
A Plates move in closer
B Plates slid past each other
C Plates moved with each other in the same direction
D Plates moved apart
Srry couldn’t find science
Answer:
Maybe (C)
...............
Answer:
A. plates move in faster
Explanation:
The convergence is a process where both the plates tend to move in closer as one plate overrides the other and the formation of a Himalayas is described as a range that formed by the movement of the sediments that were bought by the Tethys sea. By the collision of the Indian and the Eurasian plate.
i hope this helps
QUESTION NO.1
Anything that causes damage to the ______ and makes the _______ contaminated is called air polluton.
OPTIONS:
a) atmosphere
b) toilet
c) school
QUESTION NO.2
What are the causes of Acid Rain?
ANS:_____________________________________
Answer:
answer 1) Atmosphereanswer 2) Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.MARK ME AS BRAINLIST1 ans is atmosphere
2 ans is Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions. It can have harmful effects on plants, aquatic animals, and infrastructure.
True or False Weather is the condition or earth's atmosphere at a certain place and time.
Answer:
True
Explanation:
Weather is short term, climate is over the long term
Answer:
true, different weather patterns are found all around the world at different times, there could be a hurricane in the gulf of mexico and as a result of the storm tornadoes could break out in texas
Explanation:
Identify the components of the ionic formula based on the name strontium phosphide. What is the symbol for the element that forms the positive cation? What is the symbol for the element that forms the negative anion? What is the subscript on the cation in the neutral formula? What is the subscript on the anion in the neutral formula?
Answer: The components are Strontium (Sr) and Phosphorous (P). The symbol for the element that forms the positive cation is [tex]Sr^{2+}[/tex]. The symbol for the element that forms the negative anion is [tex]P^{3-}[/tex]. The subscript on the cation in the neutral formula is 3 and the subscript on the anion in the neutral formula is 2.
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here in strontium phosphide , element strontium is having an oxidation state of +2 called as [tex]Sr^{2+}[/tex] cation and element phosphorous [tex]P^{3-}[/tex] is an anion with oxidation state of -3. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral strontium phosphide [tex]Sr_3P_2[/tex]
Which of the following Noble Gases has only 2 valence electrons because it only has 1 energy level?
Helium (He)
Neon (Ne)
Argon (Ar)
Krypton (Kr)
Answer:
it is he
Explanation:
beacuse Noble gases have 2 volence
Carbon dioxide non examples? Please and catalyst non examples?
Answer:
I guess you mean by non element example. Non element examples have more than one elements. Carbon dioxide is a non element example since caebon dioxide has 2 oxygen atoms + 1 carbon atom = carbon dioxide.
I think catalyst is also a non element example because catalyst is inorganic which means that it is not a living thing. Since catalyst is in brass and brass is a non element example, I think catalyst is also a non element example.
Hope that helps, thank you !!
If you had the same stock of the blue solution as in the serial dilution simulation you did (1M solution), and you needed 10 mL of a solution that was 1.0x10-6 M, what volume of the blue stock solution would you need, and what volume of diluent would you need to reach 10 mL of the desired concentration
Answer: We start by doing a 1/10 serial dilution, using 100 µL of 1M solution into 900 µL of water, until we get a 1.0x10^-5M (0.00001M) solution. Then use 1 mL of this 1.0x10^-5M solution into 9 mL of water.
Explanation:
To answer this question, we must use the law of conservation of mass, which states: In every chemical reaction mass is conserved, this means the total mass of the reactants is equal to the total mass of the products. The law implies that mass can neither be created nor destroyed, but it can be transformed. For example, in chemical reactions, the mass of the chemical components before the reaction is equal to the mass of the components after the reaction. Therefore, during any chemical reaction and low-energy thermodynamic processes in an isolated system, the total mass of the reactants or starting materials must be equal to the mass of the products. This law is quite accurate for low-energy processes, such as chemical reactions.
So, if the solution to be used is 1M , and a 10 mL of a 1.0x10^-6M solution is needed, we use the following equation:
Initial concentration x initial volume = final concentration x final volume.
The initial concentration is 1M, the final concentration is 1.0x10^-6M and the final volume required is 10 mL.
1M x initial volume = 1.0x10^-6M x 10 mL
initial volume= 1.0x10^-5 mL= 0.01 µL of 1M solution.
Since the final volume is 10 mL, we have to add the difference in volume with water, which is 10 mL - 1.0x10^-5 mL= 9.99999 mL.
However, since 0.01 mL is a very small volume that is difficult to take, the best option in this case is to make serial dilutions.
Usually, we start from a concentrated solution and prepare a series of dilutions to the tenth (1:10) or half (1:2). In this way a series of solutions is obtained, related for example by a dilution factor of 10, i.e. 1/10; 1/100; 1/1000 and so on.
Here we can prepare a series of dilutions to the tenth, from 1M to 1.0x10^-6.
We start by doing a 1/10 dilution, using 100 µL of 1M solution into 900 µL of water. This is a 0.1M solution. Then we take 100 µL of it into 900 µL of water to get a 0.01M solution. We continue doing that until we get a 1.0x10^-6M (0.000001M) solution. This final solution is the desired concentration, however we need 10 mL of it, and actually we have 1 mL. So we can just take 1 mL of the 1.0x10^-5M solution into 9 mL of water:
1.0x10^-5M x 1 mL = 1.0x10^-6M x 10 mL.
Sodium sulfate forms several hydrates. A sample of one of these hydrates is heated until all the water is removed. What is the formula of the original hydrate if it loses 43% of its mass when heated?
Answer:
Na₂SO₄•(H₂O)₆.
Explanation:
The mass that is lost when the sample is heated is water.
Let's assume we have 100 g of the hydrate:
43 grams would be water (H₂O), while the rest (100-43=57) would be sodium sulfate anhydrous (Na₂SO₄).
We convert both those masses to moles, using their respective molar masses:
H₂O ⇒ 43 g ÷ 18 g/mol = 2.39 molNa₂SO₄ ⇒ 57 g ÷ 142.04 g/mol = 0.40 molWe can write those results as (Na₂SO₄)₀.₄₀•(H₂O)₂.₃₉. Now we just need to multiply those numbers so that they become integers.
If we multiply both coefficients by 5 we're left with (Na₂SO₄)₂•(H₂O)₁₂.
Simplify and thus the final answer is Na₂SO₄•(H₂O)₆.
Density of water calculation using a 10 mL graduated cylinder
10 mL graduated cylinder + 10 mL unknown liquid (g) 10 mL graduated cylinder (g) Volume of liquid (mL) Density (g/mL)
Trial 1 19.731 9.861 10.0
Trial 2 19.831 9.861 10.0
Trial 3 19.831 9.861 10.0
Trial 4 19.771 9.861 10.0
Trial 5 19.751 9.861 10.0
Required:
Calculate the average density for the gradudated cylinder measurements.
Answer:
Average density of the liquid = 0.992 g/mL
Explanation:
Density = mass/volume
mass of liquid = (mass of liquid + mass of cylinder) - mass of cylinder
Trial 1: mass of liquid = 19.731 - 9.861 = 9.87
volume of liquid = 10 mL
density of liquid = 9.87 g / 10 mL = 0.987 g/mL
Trial 2: mass of liquid = 19.831 - 9.861 = 9.97
volume of liquid = 10 mL
density of liquid = 9.97 g / 10 mL = 0.997 g/mL
Trial 3: mass of liquid = 19.831 - 9.861 = 9.97
volume of liquid = 10 mL
density of liquid = 9.97 g / 10 mL = 0.997 g/mL
Trial 4: mass of liquid = 19.771 - 9.861 = 9.91
volume of liquid = 10 mL
density of liquid = 9.91 g / 10 mL = 0.991 g/mL
Trial 5: mass of liquid = 19.751 - 9.861 = 9.89
volume of liquid = 10 mL
density of liquid = 9.89 g / 10 mL = 0.989 g/mL
Average density = (0.987 + 0.997 + 0.997 + 0.991 + 0.989)/5 = 4.961/5
Average density of the liquid = 0.992 g/mL
Which of the following elements would be considered a compound? CH, Si, F, O6
Answer:
CH
Explanation:
CH, a typical sample of the compound contains one atom of carbon (C) to one atom of hydrogen (H).
what is the chemical symbol for fluoride
Answer:
I think F
Explanation:
If 80% of the moths are dark and you have 80 moths, how
many would be dark??
Answer:
the answer is 64 moths are dark
what the the noble gas configuration for Boron
Answer:
[He]2[tex]s^{2}[/tex]3[tex]p^{1}[/tex]
Explanation:
The electron configuration for Boron is 1[tex]s^{2}[/tex]2[tex]s^{2}[/tex]3[tex]p^{1}[/tex], but you can also write it as the noble gas configuration, which is [He]2[tex]s^{2}[/tex]3[tex]p^{1}[/tex]
Note that helium has the configuration of 1[tex]s^{2}[/tex], so we instead of writing it, we write [He]. This can be useful when writing the configurations of elements from the later periods as it saves space.
Which best describes a hydrate?
A.) It has water molecules bonded directly to it.
B.) It lacks water molecules ik it’s crystal lattice.
C.) It lacks hydrogen and oxygen atoms, which make up water.
D.) It has water molecules incorporated into its crystal lattice.
I’ll give you a lot of points and mark you brainlist if you awnse all 3
Answer:
Magma
Volcanic glass
Granite and pumice
Explanation:
Answer:
Magma,
Volcanic Glass,
Granite and Pumice,
Lava
Explanation:
What does CoH12O6 tell you about the glucose molecule?
Answer:
Glucose = C6H12O6
molecular mass = 6(12) + 12(1) + 6(16)
= 72 + 12 + 96
= 180 g
Explanation:
Glucose has a chemical formula of: C6H12O6 That means glucose is made of 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms. ... Glucose is produced during photosynthesis and acts as the fuel for many organisms.
what is this for questions 2
Answer:
I think is D
Explanation:
PLEASE MARK ME AS BRAINLIEST
A solution is prepared by dissolving 10.6 g sodium carbonate in enough water to produce
500.0 mL solution. What is the molarity of sodium carbonate in the solution?
Answer:
0.2mol/dm³
Explanation:
Given parameters:
Mass of Na₂CO₃ = 10.6g
Volume of solution = 500mL
Unknown:
Molarity of solution = ?
Solution:
The molarity of a solution can be determined using the expression below:
Molarity = [tex]\frac{number of moles }{volume}[/tex]
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = [tex]\frac{10.6}{106}[/tex] = 0.1mol
Convert mL to dm³;
500mL will give 500 x 10⁻³dm³or 0.5dm³
So;
Molarity = [tex]\frac{0.1}{0.5}[/tex] = 0.2mol/dm³
Different substances require different amounts of heat to change their temperature by a given amount. This behavior of the materials is called the specific heat and is a characteristic of each material.
a. True
b. False
Answer: True
Explanation:
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
It is dependent on the type of material and is fixed for a particular type of material. For example: The specific heat capacity of iron material is fixed and the value is [tex]0.444J/g^0C[/tex]
Which of the following is an example of a mixture and not a compound?
O Water
O Salt
O Lemonade
O Carbon Dioxide
Mara and ivy are asked to identify two minerals in science class. To do this, they decided to study the physical properties of the minerals in the following ways.
1 examine how they freeze
2 determine how they break
3 rub them on a white tile plate . What is the best method for the girls to study the physical properties and
Answer:
2 only is a pretty accurate answer the others dont make sense to me.
Explanation:
Answer: determine how they break
Explanation: :)
I can ride my bicycle at a velocity of 5.655 X 10° um/sec. Is this fast or slow? Prove your answer by converting into km/hr.
answer ASAP
Answer:
56/hr
Explanation:
PLEASE HELP 100 POINTS
Write a paragraph (3-4 complete sentences) using at least of the vocabulary words demonstrating how nitrogen is recycled throughout the ecosystem. (using these words)
Nitrogen Nitrates Ammonium
Nitrites Nitrogen Fixation Denitrification
Answer:
Gaseous nitrogen (78% in air) is fixed (by nitrogen fixing bacteria, and during lightning), then absorbed and assimilated by plants in the form of proteins, as well as nucleic acids. ... Nitrogen is returned to soil with excretory materials of animals and dead organisms.
Explanation:
Nitrates (or nitrites) are natural chemicals that are found in the soil, air and water. Nitrates are also used as a food additive to stop the growth of bacteria and to enhance the flavor and color of foodsAmmonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (NR + 4. ), where one or more hydrogen atoms are replaced by organic groups (indicated by R).an obsessive interest in or feeling about someone or something.
"our fixation with diet and fitness"
Denitrification: the loss or removal of nitrogen or nitrogen compounds specifically : reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air