Answer:
A1: Z
A2: Y
Explanation:
Q1: Z is the only one with a melting point high than 20 °C.
Q2: Y is the only substance with both a melting point lower than 50 °C and a boiling point higher than 50°C
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 much energy is needed to heat enough water to make a cup of tea (250 ml), if the water is initially at 20.0°C and you want to increase the temperature to 85.0°C? (1.00 mL of water has a mass of 1.00 g.)
As the tea in the previous question steeps, it cools from 85.0°C to 75.0°C. How much energy is lost by the tea as it steeps?
Answer:
Heat Energy needed (Q) = 68250 J
Energy lost (Q') = 10500 J
Explanation:
Applying,
Q = cm(t₂-t₁)............. Equation 1
Where Q = heat energy needed, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature.
From the question,
Given: m = 250 g = 0.25 kg, t₁ = 20.0°C, t₂ = 85.0°C
Constant: c = 4200 J/kg°C
Substitute these values into equation 1
Q = 0.25(4200)(85-20)
Q = 68250 J.
Similarly, heat lost
Q' = cm(t₁-t₂)................. Equation 2
Where Q = heat lost
Given: t₁ = 85°C, t₂ = 75°C
Substitute into equation 2
Q' = 4200(0.25)(85-75)
Q' = 10500 J
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
what is the lewis dot structure for AgBr? PLS HELP ME
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.
What type of reaction is shown below?
H202 + H2O + O2
Single replacement
Combustion
Synthesis
Decomposition
Answer:
Decomposition Reaction
State the method you will use to separate the following substances. (a) calcium carbonate from table salt (b) iodine from sodium chloride (c) table salt from seawater (d) sugar from sugar solution (e) pure water from sewage water (f) ethanol from beer (g) yellow dye from durian ice cream
Answer:
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Answer: There are many forms of table salt: coarse salt, refined salt, iodized salt. It is a crystalline solid, white to very pale pink or gray in color, obtained from seawater or salt deposits. Salt obtained from seawater has crystals that are smaller or larger than rock salt. In nature, table salt consists mainly of sodium chloride (NaCl), but also a few other minerals (trace minerals). Table salt obtained from rock salt may appear more gray because of traces of trace minerals. Table salt is necessary for the survival of all living organisms, including humans. Table salt is involved in regulating the body's water content (liquid balance).
what is the formula for potassium sulfate
What is the formula for potassium sulfate?
[tex]\implies {\blue {\boxed {\boxed {\purple {\sf { K_{2} SO_{4} }}}}}}[/tex]
[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]
Please I need an explanation on the relationship between concentration and volume of reacting substances
Answer:
when d volume of a substance is high, the concentration is gonna b low...
Jus lyk putting much water in just a cube of sugar
Explanation:
So lower volume, higher concentration
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:
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.
Which best describes an alpha particle that is emitted during nuclear decay?
A. A helium nucleus
B. A hydrogen nucleus
C. An electron
D. A positron
Answer:
A helium nucleus
Thre types of radiation
Alpha: Helium nucleus
Beta: Electron
Gamma: Gamma rays
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❤
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.
NO2 + H2O =
SO2 + H2O =
H2S + H2O=
SO2+ H2O=H2SO3
H2S+ H2O=H2SO4 +H2
NO2+ H2O= HNO3+NO
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.
Write the four quantum numbers of the outermost two electrons in the atom of calcium
Answer:
Its electron configuration is: 2 electrons in the K shell (principal quantum number 1), 8 in the L shell (principal quantum number 2), 8 in the M shell (principal quantum number 3), and 2 in the N shell (principal quantum number 4).
Explanation:
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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
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 ........
Write a letter to someone who had bullied you in the past,
Answer:
frick u beotch
Explanation:
What is the ratio of sodium ion to phosphate ion
in the formula Na3PO4?
Answer:
42,07%and 18,90%
Explanation:
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......
All samples of a specific substanice have the same chemical
composition
TRUE
FALSE
Answer:
true
Explanation:
E. Give reasons
1. Oxygen is a diatomic element.
3. The valency of sodium is one.
F. Differentiate between
1. electrovalent bond and covalent bond
2. acidic radical and basic radical
Answer:
the valency of sodium is one because sodium loses 1 electron to become stable
You have 5000 atoms of gold and 5000 atoms of silver. Which statement is true.
You have the same mass of each.
You have the same number of moles of each.
Both are true.
Neither are true.
"You have the same number of moles of each." is the true statement.
The mass of Gold and Silver differ, so that first statement can't be true because the quantities are the same. Because a mole measures solely amounts, like a dozen does, you will have the same amount of moles if the quantities are the same.
How many mL of 0.013 M potassium hydroxide are required to reach the equivalence point in the titration of 75 mL 0.166 M hydrocyanic acid?
Answer:
957.7mL
Explanation:
Using the formula below;
CaVa = CbVb
Where;
Ca = concentration of acid (M)
Va = volume of acid (mL)
Cb = concentration of base (M)
Vb = volume of base (mL)
According to the information provided in this question:
Ca = 0.166 M
Cb = 0.013 M
Va = 75mL
Vb = ?
Using CaVa = CbVb
0.166 × 75 = 0.013 × Vb
12.45 = 0.013Vb
Vb =12.45/0.013
Vb = 957.7mL
what is the balanced equation of magnesium carbonate decomposes on heating to form magnesium oxide and carbon dioxide
Answer:
ExplaAt high temperatures MgCO3 decomposes to magnesium oxide and carbon dioxide. This process is important in the production of magnesium oxide. This process is called calcining: MgCO3 → MgO + CO2 (ΔH = +118 kJ/mol)
nation:
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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.
The number of molecules in 17.9 g of CO is
Answer:
3.85 × 10²³ molecules CO
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableCompoundsMolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
Identify
[Given] 17.9 g CO
[Solve] molecules CO
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of C: 12.01 g/mol
[PT] Molar Mass of O: 16.00 g/mol
Molar Mass of CO: 12.01 + 16.00 = 28.01 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 17.9 \ g \ CO(\frac{1 \ mol \ CO}{28.01 \ g \ CO})(\frac{6.022 \cdot 10^{23} \ molecules \ CO}{1 \ mol \ CO})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 3.8484 \cdot 10^{23} \ molecules \ CO[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
3.8484 × 10²³ molecules CO ≈ 3.85 × 10²³ molecules CO