is the Halloween clock reaction a physical or chemical change

Answers

Answer 1

Answer:

IT IS A CHEMICAL CHANGE

Explanation:

The Old Nassau reaction or Halloween reaction is a chemical clock reaction in which a clear solution turns orange and then black

Answer 2

Answer:

It's a chemical change.


Related Questions

A human hair is 75 um across. How many inches is this?

Answers

Answer:

2.9528e-6

Explanation:

or 0.0029

Acid formulas usually start with ______________ because they have hydrogen atoms combined with other atoms in their molecules

Answers

Answer:

H

Explanation:

Example,

HCl for hydrochloric acid

H2SO4 for sulphuric acid

HNO3 for nitric (v) acid

A sample of copper has a density of 10.50g/cm3 and measures of 0.400 dm long,20.0 mm high and 0.003 m thick. What is the mass in grams of this block of copper metal?

Answers

the mass in grams is 60 grams of copper metal.

QUESTION TWO
2.1
Discuss the process of the scientific method and clarify what is meant
by the science process skills.
(5)

Answers

Answer: The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observation.

Explanation:

Hope this helps. :)

6621.5 kJ of heat is required to convert a 20.5 g sample of
aluminum from the solid to liquid phase. What is the heat of
fusion of aluminum in kJ/g?
kJ/g

Answers

Answer:

323 kJ/g

Explanation:

ck-12 said it was correct


someone help with this will mark brainliest

Answers

Answer:

The main difference between emission and absorption spectra is that an emission spectrum has different coloured lines in the spectrum, whereas an absorption spectrum has dark-coloured lines in the spectrum.l

periodic table for the first twenty elements​

Answers

Answer:

periodic table for the first twenty elements

Answer:

Explanation:

hope this helps

In an ocean wave, what happens to a water molecule after it transfers its kinetic energy to another water molecule?

Answers

In sound waves, energy is transferred through vibration of air particles or particles of a solid through which the sound travels. ... In water waves, energy is transferred through the vibration of the water particles.

1. During an endothermic chemical reaction, a gas is consumed and a liquid produced.

a. Yes.
b. No.
c. Can't decide with information given.

2. A gas condenses to a liquid, neither absorbing nor releasing heat.

a. Yes.
b. No.
c. Can't decide with information given.

Answers

1. No
2.No
I hope this helps:)

The compound borazine consists of 40.29% boron, 7.51%
hydrogen, and 52.20% nitrogen, and its molar mass is
80.50 g/mol. Calculate the molecular formula for borazine.

Answers

Answer:

[tex]B_3H_6N_3[/tex]

Explanation:

Hello there!

In this case, since the mass percentages in a compound which is wanted to know the molecular formula, can be assumed to be the masses, we first need to compute the moles they have in the formula unit:

[tex]n_B=40.29gB*\frac{1molB}{10.811gB} =3.73molB\\\\n_H=7.51gH*\frac{1molH}{1.01gH} =7.44molH\\\\n_N=52.20gN*\frac{1molN}{14.01gN} =3.73molN[/tex]

Next, we divide each moles by the fewest ones (3.73 mol) in order to find the subscript in the empirical formula first:

[tex]B:\frac{3.73}{3.73}=1 \\\\H:\frac{7.44}{3.73}=2\\\\N:\frac{3.73}{3.73}=1[/tex]

Then, the empirical formula is BH2N whose molar mass is 26.83 g/mol, so the ratio of molecular to empirical is 80.50/26.83=3; therefore, the molecular formula is three times the empirical one:

[tex]B_3H_6N_3[/tex]

Best regards!

Question 1
Describe a procedure you could follow to determine the specific heat of a 45-g piece of metal.

Answers

First we put the known mass of water in the calorimeter and than measure temperature. Heat that metallic sample to boiling water at 100°C.
now that hot metal sample we will put into calorimeter and than wait for it till the water get at its constant stabilizes temperature.
finally we measure temperature of water. we consider no heat around there and now calculate specific heat of the metal by equating the amount of heat lost by the metal to the amount of

At 2000 ∘C the equilibrium constant for the reaction 2NO(g)⇌N2(g)+O2(g) is Kc=2.4×103. If the initial concentration of NO is 0.175 M , what is the equilibrium concentration of N2?

Answers

Answer:

[tex][N_2]=0.0866M[/tex]

Explanation:

Hello there!

In this case, in agreement to the chemical reaction, it is possible for us to figure out the equilibrium concentration of the N2 product, via an ICE table plugged in the equilibrium expression:

[tex]Kc=\frac{[N_2][O_2]}{[NO]^2}\\\\2.4x10^3=\frac{x*x}{(0.175-2x)^2}[/tex]

In such a way, when solving for x via quadratic equation or just a solver, it is possible to obtain:

[tex]x_1=0.0866M\\\\x_2=0.0884M[/tex]

In such a way, since the root 0.0884 M produce a negative concentration of NO (0.175-2*0.0884=-0.0018M), we infer that the correct root is 0.0866 M; therefore, the concentration of N2 at equilibrium is equal to x:

[tex][N_2]=x=0.0866M[/tex]

Best regards!

Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]

Answers

A). 10-14 / [H3O+]
Explanation:
Hydronium (H3O+) and hydroxide ions (OH-) are both present in pure water and in all aqueous solutions.
Their respective concentrations in water are 10^-7 M each and are inversely proportional to each other as given by the ion product of water, Kw.
Kw = [H3O+][OH−]
Where Kw = 1.0 * 10^-14,
[H3O+] = concentration of hydronium ions
[OH-] = concentration of hydroxide ions
Therefore, [OH-] = Kw / [H3O+]
[OH-] = 10^-14/[H3O+]

How many hydrogen atoms are present in H2SO4+H2O?

Answers

Four hydrogen atoms






can be used to help an individual with an eating disorder learn better ways to cope with stress an
replace unhealthy behaviors with those that do not cause harm.
A. Preventative care
B. Hospitalization
C. Medication
D. Psychotherapy

Answers

Answer: Psychotherapy

Explanation:

Edge

Answer:

D. Psychotherapy

Explanation:

Did the test

Which of the following environments are low-level areas that can be temporarily or seasonally filled with water?

Rainforest

Swamp

Tundra

Wetland giving brainlist HAS TO BE RIGHT

Answers

Answer:

Rainforest

Explanation:

Swamps are permanently filled with water

and Tundras are dry and cold so the answer should be Rainforest

Answer:

its rainforest it's a it's

Explanation:

4) Which of the following can cause erosion?
- Glaciers, wind, and animals
- Acid rain, animals, and ice wedging
- Wind, water, glaciers
- Glaciers, wind, and acid rain

5) Which factors affect the rate of weathering?
- Temperature, ocean currents, and tides
- Type of rock and amount of precipitation
- Type of plants and animals
- Amount of sunlight

Answers

Water, air, and even ice are fluids because they tend to flow from one place to another due to the force of gravity.

Rainfall and temperature can affect the rate in which rocks weather. High temperatures and greater rainfall increase the rate of chemical weathering. 2. Rocks in tropical regions exposed to abundant rainfall and hot temperatures weather much faster than similar rocks residing in cold, dry regions.

Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.32 × 1014 Hz.

Answers

Answer:

474 nm or 4.74 x 10^2 nm

Explanation:

c = λv

c (speed of light) = 2.998 x 10^8 m/s

λ = ?

v = 6.32 × 1014 Hz = 6.32 × 1014 1/s

2.998 x 10^8 m/s = (λ)(6.32 × 10^14 1/s)

λ = (2.998 x 10^8 m/s) / (6.32 × 10^14 1/s)

λ = 4.74 x 10^-7 m

λ = 4.74 x 10^-7 m x (1 x 10^9 nm/1 m) = 474 nm

calculate the amount of heat energy required to heat up 23.2 grams of ice from -21° C to 56° C ** please show your work**

Answers

The second option 1,870.4 Joules

which of the following human activities are not related to an increase in global temperature

Answers

list the activities pls

How many moles of Hydrogen fluoride are formed from 10 moles of fluorine?

Answers

200.063

Hope this helps :T

Explain why the upper phase, after reflux, contained the 1-bromopentane, even though its expected density is 1.276 g/cm3, and the density of water is ~1.00 g/cm3. Think what is in the aqueous solution (e.g., what is the density of salt water

Answers

Answer:

The water is not pure i.e. It contains some hydroxide and bromobutane ions that is why the upper phase contains 1-bromopentane

Explanation:

The upper phase after reflux will contain 1-bromopentane even when its density is 1.276g/cm^3 because even though the density of water = 1.00g?cm^3  the water is not pure i.e. It contains some hydroxide and bromobutane ions making it to stay at the bottom while 1- bromobutane stays at the upper phase

Calculate the number of miles of magnesium,chlorine, and oxygen atoms in 5.00 moles of magnesium perchlorate

Answers

Answer:

5.00 mol Mg

10.0 mol Cl

40.0 mol O

Explanation:

Step 1: Given data

Moles of Mg(ClO₄)₂: 5.00 mol

Step 2: Calculate the number of moles of Mg

The molar ratio of Mg(ClO₄)₂ to Mg is 1:1.

5.00 mol Mg(ClO₄)₂ × 1 mol Mg/1 mol Mg(ClO₄)₂ = 5.00 mol Mg

Step 3: Calculate the number of moles of Cl

The molar ratio of Mg(ClO₄)₂ to Cl is 1:2.

5.00 mol Mg(ClO₄)₂ × 2 mol Cl/1 mol Mg(ClO₄)₂ = 10.0 mol Cl

Step 4: Calculate the number of moles of O

The molar ratio of Mg(ClO₄)₂ to Cl is 1:8.

5.00 mol Mg(ClO₄)₂ × 8 mol O/1 mol Mg(ClO₄)₂ = 40.0 mol O

first American president​

Answers

Answer :-

George Washington was the first American President.

:^

Calculate the mass of a sample of CaCl2 containing 2 mol of this substance​

Answers

Answer:

221.96 g

Explanation:

Step 1: Given data

Moles of calcium chloride (n): 2 mol

Step 2: Calculate the molar mass of calcium chloride

The molar mass of the compound is equal to the sum of the molar masses of the elements that form it.

M = 1 × M(Ca) + 2 × M(Cl)

M = 1 × 40.08 g/mol + 2 × 35.45 g/mol = 110.98 g/mol

Step 3: Calculate the mass (m) of calcium chloride

We will use the following expression.

m = n × M

m = 2 mol × 110.98 g/mol = 221.96 g

Calculate the number of nickel atoms in a 5-cent coin of mass 0.942g if it was made of an alloy consisting of 75% copper and 25% nickel.

Answers

Answer:

2.41x10²¹ atoms

Explanation:

First we calculate the mass of nickel in the coin, using the given mass and percent composition:

0.942 g * 25/100 = 0.2355 g Ni

Then we convert 0.2355 grams of nickel to moles, using its molar mass:

0.2355 g Ni ÷ 58.69 g/mol = 0.004 mol

Finally we convert moles into number of atoms, using Avogadro's number:

0.004 mol * 6.023x10²³ atoms/mol = 2.41x10²¹ atoms

If 1.3 moles of silicon dioxide react with 2.5 moles of carbon, how many grams of carbon
monoxide form?

Answers

Answer:

46.76 g

Explanation:

The reaction that takes place is:

SiO₂ + 3C → SiC + 2CO

First we determine the limiting reactant:

1.3 moles of SiO₂ would react completely with (3 * 1.3) 3.9 moles of C. There are not as many C moles, meaning that C is the limiting reactant.

Now we convert C moles (the limiting reactant) into CO moles, using the stoichiometric coefficients:

2.5 mol C * [tex]\frac{2molCO}{3molC}[/tex] = 1.67 mol CO

Finally we convert 1.67 moles of CO to grams, using its molar mass:

1.67 mol CO * 28 g/mol = 46.76 g


A blend or combination of genetic material of the parents.
Question 2
What do variations of inherited traits between parent and offspring arise from?

Answers

Answer:

Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited.

Explanation:

The sky on Earth is blue because blue light is scattered through the atmosphere as the other colors of light pass
through undisturbed. Which nebulae have something similar happening?
Emission nebulae
Dark nebulae
Reflection nebulae
Planetary nebulae

Answers

Answer:

C

Explanation:

Plz help me plz I am timed!!

Answers

Answer:

full moon

Explanation:

....ur welcome..............

Answer:

full moon

Explanation:

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