Describe what parts are required to make an electric cell

A metal object has a mass of 8.37g. When it was in a graduated cylinder containing 20.0 ml of water, the water level rose to 23.

Yuri [45]

Mass of metal is 8.37 g, volume of water in graduated cylinder is 20 mL. After adding the metal, water level increases to 23.1 mL. The volume of metal is equal to the increase in water level.

The increase in water level can be calculated by taking difference of final and initial level of water.

Thus,

$V_{metal}=V_{f}-V_{i}=(23.1-20)mL=3.1 mL$

Density of metal is defined as mass per unit volume of metal. It can be calculated as follows:

$d=\frac{m}{V}=\frac{8.37 g}{3.1 g/mL}=2.7 g/mL$

This value corresponds to the density of aluminum.

Therefore, density is 2.7 g/mL and metal is aluminum.

3 0

4 years ago

What is a atom of chemistry

Yuliya22 [10]

Answer:

Atom is the smallest particle of matter.

Elements are made up of same atoms.

Atom consist of electron, proton and neutron.

Explanation:

Atom was first discovered by John Dalton.

word "Atom" came from Greek word, that means something that could not split. he explained that atom is indivisible particle.

In the end of 18th century J.J. Thomson put forward a new concept of atom. he said that atom have negative charged particles called electrons but overall atom is neutral.

In 1909 Rutherford with his students discovered positive charged particles and nucleus and said that it is in the center of atom.

He explain a model of atom and said that electrons revolve around a hard core in the center called nucleus.

In 1913 Niels Bohr explains the atomic spectra and put forward the concept of shells and sub-shells.

So overall Structure of an Atom is

consist of Neutrons in nucleus
+ve charged protons in nucleus
A -vely charged electrons revolving around the nucleus
the electron revolve in shells i.e. K, L, M, and N
Each shell divide in sub-Shell such as s, p,d and f.

Atom has a specific atomic mass and atomic number

Atomic number = number of protons or electron

Atomic mass = number of protons + number of neutrons in nucleus.

8 0

4 years ago

For the reaction A + B + C → D + E, the initial reaction rate was measured for various initial concentrations of reactants. The

Alik [6]

Answer : The rate for trial 5 will be $4.25\times 10^{-2}Ms^{-1}$

Explanation :

Rate law is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

$A+B+C\rightarrow D+E$

Rate law expression for the reaction:

$\text{Rate}=k[A]^a[B]^b[C]^c$

where,

a = order with respect to A

b = order with respect to B

c = order with respect to C

Expression for rate law for first observation:

$6.0\times 10^{-4}=k(0.20)^a(0.20)^b(0.20)^c$ ....(1)

Expression for rate law for second observation:

$1.8\times 10^{-3}=k(0.20)^a(0.20)^b(0.60)^c$ ....(2)

Expression for rate law for third observation:

$2.4\times 10^{-3}=k(0.40)^a(0.20)^b(0.20)^c$ ....(3)

Expression for rate law for fourth observation:

$2.4\times 10^{-3}=k(0.40)^a(0.40)^b(0.20)^c$ ....(4)

Dividing 1 from 2, we get:

$\frac{1.8\times 10^{-3}}{6.0\times 10^{-4}}=\frac{k(0.20)^a(0.20)^b(0.60)^c}{k(0.20)^a(0.20)^b(0.20)^c}\\\\3=3^c\\c=1$

Dividing 1 from 3, we get:

$\frac{2.4\times 10^{-3}}{6.0\times 10^{-4}}=\frac{k(0.40)^a(0.20)^b(0.20)^c}{k(0.20)^a(0.20)^b(0.20)^c}\\\\4=2^a\\a=2$

Dividing 3 from 4, we get:

$\frac{2.4\times 10^{-3}}{2.4\times 10^{-3}}=\frac{k(0.40)^a(0.40)^b(0.20)^c}{k(0.40)^a(0.20)^b(0.20)^c}\\\\1=2^b\\b=0$

Thus, the rate law becomes:

$\text{Rate}=k[A]^2[B]^0[C]^1$

Now, calculating the value of 'k' by using any expression.

Putting values in equation 1, we get:

$6.0\times 10^{-4}=k(0.20)^2(0.20)^0(0.20)^1$

$k=7.5\times 10^{-2}M^{-2}s^{-1}$

Thus, the value of the rate constant 'k' for this reaction is $7.5\times 10^{-2}M^{-2}s^{-1}$

Now we have to calculate the rate for trial 5 that starts with 0.90 M of reagent A, 0.60 M of reagents B and 0.70 M of reagent C.

$\text{Rate}=k[A]^2[B]^0[C]^1$

$\text{Rate}=(7.5\times 10^{-2})\times (0.90)^2(0.60)^0(0.70)^1$

$\text{Rate}=4.25\times 10^{-2}Ms^{-1}$

Therefore, the rate for trial 5 will be $4.25\times 10^{-2}Ms^{-1}$

3 0

3 years ago

HELP MEEEE ASAP!!! Answer these questions based on what you learned from the passage. You can assume any body structure comes fr

erica [24]

Answer:

1.Legs

2.Arms and hands

3.Armor

4.Skeletal

5.Carpenters

6.Brain

7.Skin

8.Blood

Explanation:

You can google dem and it will show you all the answers

4 0

4 years ago

Can a substance be a Lewis acid without being a Bronsted-Lowry acid?<br> Please argue on it

makkiz [27]

Answer:

Yes. Since for a substance to be a Bronsted-Lowry acid they have to be able to donate protons, and to be a Lewis acid a substance would have to accept electrons, there are substances which cannot donate protons but can accept electrons.

Explanation:

Hope this helped!

5 0

3 years ago