Answer:
Answer is A... Melting and freezing
When magnesium ribbon is placed in sulfuric acid, a chemical reaction takes place and heat energy is given off. Liang and Narabaatar are planning an investigation into the effect of the length of magnesium ribbon on the increase in temperature. They decide to carry out some preliminary work.
Explain what preliminary work they could do and how this would help them plan their investigation.
please give a genuine aswer
Answer:
this is the answer
I hope it helps you although
A gas has a pressure of 2.36 kPa at 62 °C. What is the pressure at standard
temperature?
Answer:
P2 = 1.94 kPa
Explanation:
Given the following data;
Initial pressure = 2.36 kPa
Initial temperature = 62°C
Standard temperature = 0°C
Conversion:
Kelvin = 273 + C
Kelvin = 273 + 62 = 335 K
Kelvin = 273 + 0 = 273 K
To find the final pressure, we would use Gay Lussac's law;
Gay Lussac states that when the volume of an ideal gas is kept constant, the pressure of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Gay Lussac's law is given by;
[tex] PT = K[/tex]
[tex] \frac{P1}{T1} = \frac{P2}{T2}[/tex]
Making P2 as the subject formula, we have;
[tex] P_{2}= \frac{P1}{T1} * T_{2}[/tex]
[tex] P_{2}= \frac{2.36}{335} * 273 [/tex]
[tex] P_{2}= 0.0071 * 273 [/tex]
P2 = 1.94 kPa
2. Evaluate :
(i) 28 : 23
Answer:
28/23
Explanation:
28 : 23
this is written as ,
28/23
u can convert into simplest form but in this question u can't so leave it as it is.
A 125 mL sample of phosphoric acid was titrated with an average of 63.7 mL of a 0.050M barium hydroxide solution according to the given reaction: 2 H3PO4 + 3 Ba(OH)2 ⇌ Ba3(PO4)2 + 6 H2O Determine the concentration of the phosphoric acid sample:
Answer:
0.017 M
Explanation:
The balanced equation for the reaction is given below:
2H₃PO₄ + 3Ba(OH)₂ ⇌ Ba₃(PO₄)₂ + 6H₂O
From the balanced equation above,
The mole ratio of acid, H₃PO₄ (nₐ) = 2
The mole ratio of base, Ba(OH)₂ (n₆) = 3
Finally, we shall determine the concentration of the phosphoric acid, H₃PO₄. This can be obtained as follow:
Volume of acid, H₃PO₄ (Vₐ) = 125 mL
Volume of base, Ba(OH)₂ (V₆) = 63.7 mL
Concentration of base, Ba(OH)₂ (C₆) = 0.050M
Concentration of acid, H₃PO₄ (Cₐ) =?
CₐVₐ / C₆V₆ = nₐ/n₆
Cₐ × 125 / 0.05 × 63.7 = 2/3
Cₐ × 125 / 3.185 = 2/3
Cross multiply
Cₐ × 125 × 3 = 3.185 × 2
Cₐ × 375 = 6.37
Divide both side by 375
Cₐ = 6.37 / 375
Cₐ = 0.017 M
Thus, the concentration of the phosphoric acid, H₃PO₄ is 0.017 M
How does chemistry affect the food you eat?
A.
All food can be analyzed to determine what nutrients they contain.
B.
Some fruits and vegetables may be genetically modified to resist diseases.
C.
Food can be transported in containers that keep it at safe temperatures.
D.
Some meats may be vacuum sealed to preserve their freshness.
Answer:
A
Explanation:
Blue litmus paper is used to determine the acidity of a compound. When litmus paper detects hydrogen ions (H+), the paper turns red. Which solution will leave the blue litmus unchanged in color? hydrochloric acid (HCI) hydrobromic acid (HBr) B C sodium hydroxide (NaOH) sodium chloride salt (NaCl)
A. Hydrochloric acid (HCI)
B. Hydrobromic acid (HBr)
C. sodium hydroxide (NaOH)
D. sodium chloride (NaCI)
Answer:
Bases Do not Change the Color of Blue Litmus.
I'd go with Option C.
Sodium Hydroxide.
What is the ratio of sodium ion to phosphate ion
in the formula Na3PO4?
Answer:
42,07%and 18,90%
Explanation:
Why do we need to know these organic molecules?
Are they important to living things?
Answer:
Organic molecules are important to living things because life is based on the properties of carbon.
Properties of Carbon
Carbon is an important element because it can form four covalent bonds.
Carbon skeletons can vary in length, branching, and ring structure.
The carbon skeletons contain the functional groups that are involved in biochemical
Explanation:
Hope it helps
HELP
our response should be at least 5-7 sentences at a minimum.
Question: A chemical reaction absorbs energy when occurring. Is this reaction Exothermic or Endothermic? If the enthalpy of the reactants was 300kJ and the enthalpy of the products was 450kJ, list one possible value for the enthalpy value of the transition state (the activation energy).
Explanation:
a chemical reaction that absorbs energy is known to be endothermic since heat is being taken in by the reaction. The value of the transition state would be 150 because you have to subtract the product's enthalpy and the reactant's enthalpy to obtain it. A positive value for the transition state also corroborates that the reaction is endothermic.
Iron pieces can be separated from sand using
Answer:
A Magnet or Magnetic Filtration
Answer:
Magnetic Filtration
Explanation:
That is the answer
Select the correct answer. What is the hydronium (H3O+) concentration of a solution with a pH of 3.60?
Answer: The hydronium [tex](H_{3}O^{+})[/tex] concentration of a solution with a pH of 3.60 is 0.56 M.
Explanation:
pH of a substance is the negative logarithm of concentration of hydrogen ions present in it.
It's formula is; pH = - log [tex][H^{+}][/tex]
When pH of a solution is 3.60 then its hydronium or hydrogen ion concentration is calculated as follows.
[tex]pH = - log [H^{+}]\\3.6 = - log [H^{+}]\\concentration of H^{+} = antilog (-3.6)\\= 0.56[/tex]
Thus, we can conclude that the hydronium [tex](H_{3}O^{+})[/tex] concentration of a solution with a pH of 3.60 is 0.56 M.
X, Y, Z là ba axit cacboxylic đơn chức cùng dãy đồng đẳng (MX < MY < MZ), T là este tạo bởi X, Y, Z với một ancol no, ba chức, mạch hở E. Đốt cháy hoàn toàn 26,6 gam hỗn hợp M gồm X, Y, Z, T (trong đó Y và Z có cùng số mol) bằng lượng vừa đủ khí O2, thu được 22,4 lít CO2 (đktc) và 16,2 gam H2O. Mặt khác, đun nóng 26,6 gam M với lượng dư dung dịch AgNO3/NH3, sau khi các phản ứng xảy ra hoàn toàn thu được 21,6 gam Ag. Mặt khác, cho 13,3 gam M phản ứng hết với 400ml dung dịch NaOH 1M và đun nóng, thu được dung dịch N. Cô cạn dung dịch N thu được m
which of the following metal is a p-block element ?a.gold b.iron c.copper d.aluminium
What are the limitations of bohr's model of atom
Answer:
The Bohr Model is very limited in terms of size. Poor spectral predictions are obtained when larger atoms are in question. It cannot predict the relative intensities of spectral lines. It does not explain the Zeeman Effect, when the spectral line is split into several components in the presence of a magnetic field.
Explanation:
Answer:
espero que te ayude ........
Please help me guys to solve this problem!
(a) distance measured with metre rule or tape rule
time measured with stopwatch/ stop clock/ timer
Average speed = total distance / time
(b) (i) decrease in speed
(ii) Change in speed = a * t
4.5 m/s
hope this helps......
please answer this as quickly as possible
Explanation:
I. Because an explosion is a very fast exothermic reaction
ll. it depends on the it's particle size
What are substance made of
Answer:
Lesson Summary. A substance is simply a pure form of matter. In other words, a substance is matter than contains only one type of atom or molecule. Pure substances can be further divided into two sub-categories: elements and compounds.
Explanation:
Radhe Radhe❤
What does botanist study? A. Boats
B.Matter
C. chemicals
D. Plants
What does botanist study?
[tex]\implies {\blue {\boxed {\boxed {\purple {\sf {D.\: Plants}}}}}}[/tex]
[tex]\bold{ \green{ \star{ \orange{Hope\:it\:helps.}}}}⋆[/tex]
I have oxygen gas at 2 L and 2 atm. At what pressure is the oxygen gas if my volume decreases to 1 L?
Answer: The oxygen gas has a pressure of 4 atm if my volume decreases to 1 L.
Explanation:
Given: [tex]V_{1}[/tex] = 2 L, [tex]P_{1}[/tex] = 2 atm
[tex]V_{2}[/tex] = 1 L, [tex]P_{2}[/tex] = ?
Formula used to calculate the new pressure is as follows.
[tex]P_{1}V_{1} = P_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]P_{1}V_{1} = P_{2}V_{2}\\2 atm \times 2 L = P_{2} \times 1 L\\P_{2} = 4 atm[/tex]
Thus, we can conclude that the oxygen gas has a pressure of 4 atm if my volume decreases to 1 L.
Read temprature on thermometer i am confusion
Answer:
a)22.2°C after adding magnesium
b)17.3°C before adding magnesium
c) 4.9 is change
How does an indicator show the difference between an acid and an alkali?
Explanation:
When a base dissolves in water it is an alkali and makes an alkaline solution.
...
Litmus.
Red Litmus Blue Litmus
Acidic solution Stays red Turns red
Neutral solution Stays red Stays blue
Alkaline solution Turns blue Stays blue
Please tell me the answer
Answer:
the pair of isotopes are b and e
the element with mass no of 19 is C
the element with atomic no 7is D
Explanation:
B and E are isotopes bcos they have the same atomic no, i.e no of protons. They bother have atomic no of 17 BUT have different mass no i.e sum of neutrons and protons.
(b)C is correct because the sum of the protons and neutrons is 19
(c) D because it has 7 protons
If oxygen has 6 valence electrons how many it would like to gain to have full valence shell? And what charge will it give to oxygen ion?
Answer:
Gain 2, and become negatively charged
Explanation:
A full valence shell, thus stablilized, has 8 electrons, and so it would need two more, and when atoms gain electrons, they become negatively charged because there are now more electrons than protons (and so, when they lose electrons, they become positively charged). Hope this helps! :)
A 2.0 M solution of LiF had 4.00 moles of LiF added to a solvent to make it.
What is the volume of this solution?
A. 2 L
B. 3 L
C. 6 L
D. 8 L
Its 2L Btw
Answer:
2 L
Explanation:
From the question given above, the following data were obtained:
Molarity of LiF = 2 M
Mole of LiF = 4 moles
Volume =?
Molarity of a solution is simply defined as the mole per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole / Volume
With the above formula, we can obtain the volume of the solution as shown below:
Molarity of LiF = 2 M
Mole of LiF = 4 moles
Volume =?
Molarity = mole / Volume
2 = 4 / volume
Cross multiply
2 × volume = 4
Divide both side by 2
Volume = 4/2
Volume = 2 L
Therefore, the volume of the solution is 2 L.
Chlorine can be made by the electrolysis of sodium chloride solution. Calculate the mass of chlorine that can be formed from 50.0g of sodium chloride.???
Answer:29.9 or 30
Explanation:
Total, 30.38 grams of chlorine gas can be formed from 50.0 grams of sodium chloride through electrolysis.
To calculate the mass of chlorine that can be formed from 50.0g of sodium chloride (NaCl) through electrolysis, we need to consider the balanced chemical equation for the electrolysis of NaCl;
2 NaCl (aq) → 2 Na (s) + Cl₂ (g)
From the balanced equation, we can see that 2 moles of NaCl produce 1 mole of chlorine gas (Cl₂).
Convert given mass of sodium chloride to moles.
Molar mass of NaCl = 22.99 g/mol (Na) + 35.45 g/mol (Cl)
= 58.44 g/mol
Moles of NaCl = 50.0 g / 58.44 g/mol ≈ 0.856 mol
Calculate moles of chlorine gas formed.
From the balanced equation, 2 moles of NaCl produce 1 mole of Cl₂.
Moles of Cl₂ = 0.856 mol / 2 ≈ 0.428 mol
Convert the moles of chlorine gas to mass.
Molar mass of Cl₂ = 2 × 35.45 g/mol
= 70.90 g/mol
Mass of Cl₂ = 0.428 mol × 70.90 g/mol
≈ 30.38 g
So, approximately 30.38 grams of chlorine gas can be formed from 50.0 grams of sodium chloride through electrolysis.
To know more about chlorine gas here
https://brainly.com/question/18981083
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why is dilute tetraoxosulphate(VI) acid not suitable for preparing carbon monooxide
Answer: Because this does not dissolve in water - it forms a barrier on the surface of the unreacted CaCO3 which prevents any further reaction. A small volume of CO2 is produced , but this stops after a short time . Conclusion: H2SO4 cannot be used with CaCO3 to produce CO2 gas .
Explanation:
types of molecular forces
Answer:
Hydrogen bonds
Covalent bonds
Van Der Walls Forces
Ionic Bonding
London Dispersion forces
Metallic bonding
Chemical bonds
17. (1.09 x 102) x (2.79 x 10')
18. (5.75 x 104) / (4.71 102)
19.(3.38 x 106) x (7.80 x 104)
20. (7.04 x 10) / (9.45 x 10-)
Answer:
17. 3,101.922
18. 1.2447441822
19. 288,057.12
20. 0.74497354
El Niño begins with which of the following?
Answer:
El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. Normally, these warm water pools near Indonesia and the Philippines.
Explanation:
PLEASE HELP!
need answers to a and b !
thank you!
a) The genotype is Hh. We simply combine the two given letters together to get this genotype.
b) The phenotype is Widow's peak. The uppercase letter is the dominant allele, while the lowercase is recessive. Any presence of the dominant allele (even a single letter) will mean the dominant phenotype will present itself. We can see that HH leads to Widow's peak phenotype, so that applies to Hh as well. Only when there isn't a dominant allele at all, the genotype hh, is when the recessive phenotype will show up.