why blue intensity of copper(2)sulphate will decrease in a voltaic cell with zinc electrode in zinc sulphate solution and copper 2sulphate solution with copper electrode in it (with salt bridge)​


Answer 1


See below.


Because the copper will  be removed from the solution - it will deposit on the electrode. The Cu2+ ions will migrate to the cathode.

Related Questions


A Helium Balloon contains 24.3 moles of Helium Gas. How many grams of Helium is this? 0.165 g
6.01 g
97.2 g
1.46 x 10^25 g



C) 97.2g


Information given;

- Calculate Number of moles

- Mass of Helium

Before proceeding, it is important to know the relationship between number of moles, mass and molar mass.

Generally 1 mole of a atom weighs as much as its molar mass. Given that the molar mass of Helium is 4.00g/mol.

It means one mole of Helium weighs 4 g.

How grams then do 24.3 moles weigh?

1 mol = 4.00g

24.3 mol = x g

Cross multiplication yields;

x = (24.3 * 4) / 1

x = 97.2 g

Mass= number of moles multiply Mass of one mole
= 24.3 multiplied by 4
= 96.2

Which step of the scientific method provides the data to analyze


The experiment is conducted in order to receive data, so in order to analyze your data you'd have to look at your experiment

During an effusion experiment, oxygen gas passed through a tiny hole 2.5 times faster than the same number of moles of another gas under the same conditions. What is the molar mass of the unknown gas? (Note: the molar mass of oxygen gas is 32.0 g/mol.) 2.0 × 102 g


Mass oxygen = 32.0 g/mol
Mass of unknown gas = ???

Rate of effusion unknown gas  = x
Rate of effusion (O2) = 2.5 x

r1/r2 = sqrt(m2)/sqrt(m1)
2.5x/x = sqrt(unknown mass)/sqrt(oxygen mass)
2.5/1 = sqrt(unknown mass)/sqrt(32)
2.5 * sqrt(32) = sqrt(unknown) Square both sides.
6.25*32 = unknown mass

200 = mass of unknown gas.


The molar mass of the unknown gas is 200 g/mol. R:


We have an effusion experiment with oxygen and another unknown substance.

Oxygen effuses (v1) through a tiny hole 2.5 times faster than unknown substances (v2). It means

v1 = 2.5v2.

Molar mas of Oxygen is M1 = 32.0 g/mol.

This process can be studied by using Graham law.

Where M2 is the unknown molecular mass, all the other data are given in the problem. Replacing and isolating M2. we can fin its value:

The molar mass of the unknown gas is 200 g/mol. R:


A scientist heats a flexible container full of neon gas. What will most likely happen to the container as the gas absorbs heat? It will shrink, because the neon atoms will break apart into smaller pieces.

It will expand, because the neon atoms will get larger.

It will expand, because the neon atoms will move more quickly and get farther apart.

It will shrink, because the neon atoms will lose energy as heat, and move closer together.


As you heat gas up, the molecules move more rapidly. This pushes harder on the outside of the container, forcing it to expand. Atoms do not change in size. 
So, the answer to the second question is C. It will expand because the neon atoms will move more quickly and get farther apart.

Answer: It will expand, because the neon atoms will move more quickly and get farther apart.

Explanation: This can be explained based on Charle's law.

Charles' Law: This law states that volume is directly proportional to the temperature of the gas at constant pressure and number of moles.

   (At constant pressure and number of moles)

Thus if a gas absorbs heat at constant pressure and no of moles, the temperature of the gas increases and thus the volume also increases and thus it expands by gaining kinetic energy and moving far apart.


Calculation: If you have a pH of 5.5 for a weak acid with a pKa of 4.76, then is there more A- or more HA in the solution? Explain why in words using your knowledge of positive or negative log numbers.



There is more A⁻ than HA in the solution  


The equation for the ionization of a weak acid is

HA + H₂O ⇌H₃O⁺ + OH⁻

When HA and A⁻ are present in comparable amounts, we can use the Henderson-Hasselbalch equation:

0.74 is a positive number, and a number must be greater than one for its logarithm to be positive. That is,

& 1\\\\\textbf{[A]}^{-} & > & \textbf{[HA]}\\\end{array}" alt="\begin{array}{rcl}\dfrac{[\text{A}^{-}]}{\text{[HA]}} & > & 1\\\\\textbf{[A]}^{-} & > & \textbf{[HA]}\\\end{array}" align="absmiddle" class="latex-formula">


lets set the ratio -A/HA as R:

pH = pKa + log(R,10) => pKa + log10(R)

pH = 5.5

pKa = 4.76

R => 10^(pH - 4.76)

10^(pH - 4.76) => 5.4954

Given R (-A/HA) a number bigger than 1, then the concentration of  -A is bigger than HA



What effect does an ocean have on the climate A) rushing water from tides cools the land

B) there is no influence on climate from an ocean

C) cool ocean air causes a cool climate

D) warm ocean air causes a dry climate


A is the answer I got. 

A gas is most likely to exist at which of the following conditions? A) High temperatures and high pressures
B) High temperatures and low pressures
C) Low temperatures and high pressures
D) Low temperatures and low pressures



A gas is most likely to exist at B) High temperatures and low pressures


Ideal gas behaviour is likely to be at high temperature and low pressure .

The causes of deviations from ideal behaviour may be due to the following two assumptions of kinetic theory of gases.  

The volume occupied by gas molecules is negligibly small as compared to the volume occupied by the gas.

The forces of attraction between gas molecules are negligible.

Deviation occur for real gases with a minor difference from that of an Ideal gas.

When real gases are at low pressures and high temperatures they behave close enough to ideal gases


B. High temp and low pressure


I got an A on my chem final :) Got this right.


When liquid phosphorus trichloride is added to water, it reacts to form aqueous phosphorous acid, h3po3(aq), and aqueous hydrochloric acid?


Liquid phosphorus trichloride, PCl3, reacts exothermically with water, H2O, in a very fast reaction. The reaction then forms aqueous phosphorous acid, H3PO3(aq) and aqueous hydrochloric acid, HCl(aq).The balanced chemical reaction is as follows: PCl3 + 3 H2O → H3PO3 + 3 HCl. Its product, phosphorous acid, is an important precursor for the manufacture of other phosphorous compounds.  

Answer: check explanation


Complete question: When liquid phosphorus trichloride is added to water, it reacts to form aqueous phosphorous acid, h3po3(aq), and aqueous hydrochloric acid. express your answer as a balanced chemical equation. Identify all the phases in your answer?


The solution to the question we have here is to balance the chemical reaction. But before we do that, let us take some notes on one of the REACTANTS, Phosphorus trichloride. Phosphorus trichloride is also known as trichlorophosphine. Phosphorus trichloride is a yellow fuming liquid that has a pungent smell. The smell of Phosphorus trichloride is very similar to that of Hydrogen chloride.

Phosphorus trichloride has a molecular weight of 137.33 g/mol.

Phosphorus trichloride can react with water to form HP0(OH)2 with HCl or H3PO3 and HCl.

The balanced equations of Reaction are given below;

(1). PCl3 (l)+ 3H2O (l) --------> H3PO3 (aq) + 3HCl (aq).

(2). PCl3 (l) + 3H2O (l) ------> HPO(0H)2 (aq) + 3HCl (aq).

For the question, the reaction to use is the equation (1).

Phosphorus trichloride,PCl3 is in liquid phase, water,H2O is in liquid phase two( both reactants are in liquid phase).

H3PO4 are both in aqeous phase.


1. A cube has a mass of 40 grams. One side of the cube has a length of 3.4. What is the Density of the cube?



1.0177 g/cm³


We are given;

  • Mass of the cube = 40 grams
  • Length of the cube = 3.4 units

We are required to get the density of the cube;

  • Assuming the length is 3.4 cm
  • The volume of the cube is given by l³

Thus, Volume of the cube = 3.4 cm × 3.4 cm × 3.4 cm

                                 = 39.304 cm³

But, density = Mass ÷ volume

                    = 40 g ÷ 39.304 cm³

                    = 1.0177 g/cm³

Therefore, the density of the cube is 1.0177 g/cm³

Random Questions