Self Studies

Chemistry Test-30

Result Self Studies

Chemistry Test-30
  • Score

    -

    out of -
  • Rank

    -

    out of -
TIME Taken - -
Self Studies

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Self Studies Self Studies
Weekly Quiz Competition
  • Question 1
    4 / -1

    How do we clasify drugs?

    Solution

    The reason for the drug's classification is as follows:

    (i) The pharmacological impact is based on: To physicians this definition is helpful. It provides a whole array of drugs to classify drugs to different diseases.

    (ii) Based on action on the drugs: This is based on a drug's action on a specific biochemical process.

    (iii) Building on chemical structure: The range of drugs that share common structural characteristics and have similar pharmacological activity.

    (iv) Building on molecular structure: Many medications have the same action function on targets. In such cases this distinction is useful.

  • Question 2
    4 / -1

    H2O2 changes Cr2O72- ion to CrO5 in an acidic medium, the oxidation state of Cr in CrO5 is

    Solution
    When H2O2 is added to an acidified solution of a dichromate, Cr2O72-, aO deep blue coloured complex, chromic peroxide, CrO5 or CrO(O2)2 is formed.
    Cr2O72-+2H++4H2O--->2CrO(O2)2+5H2O
    This deep blue coloured complex.
    The oxidation state of Cr is +6 due to the presence of two peroxide linkages which can be calculated as Cr peroxide normal
    X+(-1)4+(-2)= 0
    X-6= 0
    X= +6
  • Question 3
    4 / -1

    The electrochemical cell stops working after some time because:

    Solution

    Oxidation happens at the anode and reduction at the cathode due to a potential difference between the two electrodes. As the reaction proceeds, these potentials come close to each other until they become equal. When this happens, no more electrons flow - as current exists only when there is a potential difference. This is when the cell stops working.

  • Question 4
    4 / -1

    A nuclide of the element plutonium \({ }_{94} \mathrm{Pu}^{242}\). What is the number of neutrons in its nucleus?

    Solution

    Given,

    The nuclide of the element plutonium, \(= {}_{94}Pu^{242}\)

    To Find: the number of neutrons, \(n\).

    To calculate \(n\), the formula used:

    Number of neutrons = Atomic mass - Number of protons

    \(n=A-Z\)

    A nuclide of an element denotes its symbol atomic mass(\(A\)), and number of protons(\(Z\)) of that element.

    Number of protons, \(\mathrm{Z}\) is written as a subscript of the atomic symbol, and the atomic mass(\(A\)) is written as a superscript.

    Applying the above formula:

    \(n=A-Z\)

    here, the number of protons \(\mathrm{Pu}, \mathrm{Z}=94\)

    The atomic number of \(\mathrm{Pu}, \mathrm{A}=242\)

    \(n =242-94 \)

    \(=148\)

    \(n=148\)

    Therefore, the number of neutrons is \(148\).

  • Question 5
    4 / -1

    \(\mathrm{RNH}_{2}+\mathrm{CHCl}_{3}+\mathrm{KOH} \stackrel{\Delta}{\rightarrow}\) ? The product of the reaction is:

    Solution

    The product of the reaction is \(\mathrm{RNC}\).

    The general form of the reaction is:

  • Question 6
    4 / -1

    The pollutant capable of combining with haemoglobin is ________________.

    Solution
    The pollutant capable of combining with haemoglobin is CO. It binds to haemoglobin to form carboxyhaemoglobin, which is about 300 times more stable than the oxygen-haemoglobin complex. In blood, when the concentration of carboxyhaemoglobin reaches about 3–4 per cent, the oxygen carrying capacity of blood is greatly reduced. This oxygen deficiency, results into headache, weak eyesight, nervousness and cardiovascular disorder. This is the reason why people are advised not to smoke. In pregnant women who have the habit of smoking the increased CO level in blood may induce premature birth, spontaneous abortions and deformed babies.
  • Question 7
    4 / -1

    Which of the following conditions show the polluted environment?

    a. pH of rain water = 5.6

    b. Eutrophication

    c. Biochemical oxygen demand = 10 ppm

    d. Amount of carbon dioxide in the atmosphere = 0.03%

    Solution
    The addition of phosphates in water enhances algae growth. Such profuse growth of algae, covers the water surface and reduces the oxygen concentration in water. This leads to anaerobic conditions, commonly with accumulation of abnoxious decay and animal death. Thus, bloom-infested water inhibits the growth of other living organisms in the water body. This process in which nutrient enriched water bodies support a dense plant population, which kills animal life by depriving it of oxygen and results in subsequent loss of biodiversity is known as Eutrophication.
    The amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water, is called Biochemical Oxygen Demand (BOD). The amount of BOD in the water is a measure of the amount of organic material in the water, in terms of how much oxygen will be required to break it down biologically. Clean water would have BOD value of less than 5 ppm whereas highly polluted water could have a BOD value of 17 ppm or more.
  • Question 8
    4 / -1

    Which of the following statements is incorrect?

    Solution

    When it is cold, the moisture in the air condenses on the surface of dust particles, forming tiny droplets. These droplets are colloidal in nature and form a blanket of fog or mist in the atmosphere. Clouds are colloidal systems as they are aerosols consisting of water droplets suspended in the air.

  • Question 9
    4 / -1

    \(\mathrm{Fe}(\mathrm{s})+\mathrm{CuSO}_{4}(\mathrm{aq}) \rightarrow \mathrm{FeSO}_{4}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})\)

    The above reaction is an example of a:

    Solution

    \(\mathrm{Fe}(\mathrm{s})+\mathrm{CuSO}_{4}(\mathrm{aq}) \rightarrow \mathrm{FeSO}_{4}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})\)

    The above reaction is an example of a displacement reaction. In the above reaction, iron has displaced or removed another element,copper, from copper sulphate solution.

    The reaction in which one atom or a group ofatoms of a compound is replaced by anotheratom, is called a displacement reaction. Generally,a more reactive metal displaces a less reactivemetal from its salt solution in displacementreaction.

  • Question 10
    4 / -1
    An electron, during excitation, travels a distance of nearly \(0.79 \times 10^{-9} \mathrm{m}\) in the hydrogen atom. During the deexcitation of this electron, the number of spectral lines formed is:
    Solution

    From the data, it is clear that the difference between the radii of ground state and excited state is

    \(r_{n}-r_{1}=0.79 \times 10^{-9} \mathrm{m}\)

    \(\mathrm{r}_{1}=0.0529 \times 10^{-9} \mathrm{m}\)

    \(r_{n}-0.0529 \times 10^{-9} \mathrm{m}=0.79 \times 10^{-9} \mathrm{m}\)

    \(r_{n}=0.84 \times 10^{-9} \mathrm{m}\)

    \(\mathrm{Also}, \mathrm{r}_{\mathrm{n}}=0.0529 \times 10^{-9} \times \mathrm{n}^{2}\)

    \(\frac{0.84 \times 10^{-9}}{0.0529 \times 10^{-9}}\)

    \(n^{2}=15.87 \approx 16\)

    \(n=4\)

    Thus, electrons excited from first orbit to fourth orbit and number of spectral lines \(=\frac{\left(n_{2}-n_{1}\right)\left(n_{2}-n_{1}+1\right)}{2}\)

    \(=6\)

Self Studies
User
Question Analysis
  • Correct -

  • Wrong -

  • Skipped -

My Perfomance
  • Score

    -

    out of -
  • Rank

    -

    out of -
Re-Attempt Weekly Quiz Competition
Self Studies Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Self Studies
Click on Allow to receive notifications
Allow Notification
Self Studies
Self Studies Self Studies
To enable notifications follow this 2 steps:
  • First Click on Secure Icon Self Studies
  • Second click on the toggle icon
Allow Notification
Get latest Exam Updates & FREE Study Material Alerts!
Self Studies ×
Open Now