Question:
In curing cement plasters water is sprinkled from time to time. This helps in :
In curing cement plasters water is sprinkled from time to time. This helps in :
Updated On: Jul 2, 2022
- keeping it cool
- developing interlocking needle-like crystals of hydrated silicates
- hydrating sand and gravel mixed with cement
- converting sand into silicic acid
Hide Solution
Verified By Collegedunia
The Correct Option is B
Solution and Explanation
$CaSO _{4} \cdot \frac{1}{2} H _{2} O +1 \frac{1}{2} H _{2} O \stackrel{\text { Setting }}{\longrightarrow}$
$\underset{\text{Gypsum (orthorhombic)}}{{CaSO _{4} \cdot 2 H _{2} O}} \stackrel{\text { Hardening }}{\longrightarrow} \underset{\text { Gypsum monoclinic)}}{{ CaSO _{4} \cdot 2 H _{2} O }}$
Was this answer helpful?
0
0
Top Questions on GROUP 1 ELEMENTS
- The compound which does not exist.
- JEE Main - 2023
- Chemistry
- GROUP 1 ELEMENTS
- Read the following two statements
Statement I: Ionic radius of Li+ is greater than Mg++
Statement II: Lithium and magnesium can't form superoxide- JEE Main - 2023
- Chemistry
- GROUP 1 ELEMENTS
Which of the following has the highest hydration energy?
- JEE Main - 2023
- Chemistry
- GROUP 1 ELEMENTS
- Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: Metallic sodium dissolved in liquid ammonia giving a deep blue solution which is paramagnetic.
Reasons R: The deep blue solution to the formation of amide.
In the light of the above statements, the correct answer from the options below:- NEET (UG) - 2023
- Chemistry
- GROUP 1 ELEMENTS
- In which form does \(BeCl_{2}\) exist in the solid state, vapor state and high temperature?
- JEE Main - 2023
- Chemistry
- GROUP 1 ELEMENTS
View More Questions
Questions Asked in AIEEE exam
- This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements. It is not possible to make a sphere of capacity $1$ farad using a conducting material. It is possible for earth as its radius is $6.4 \times 10^6\,m$.
- AIEEE - 2012
- electrostatic potential and capacitance
- A steel wire can sustain $100\, kg$ weight without breaking. If the wire is cut into two equal parts, each part can sustain a weight of
- AIEEE - 2012
- mechanical properties of solids
- The limiting line in Balmer series will have a frequency of (Rydberg constant, $R_{\infty}=3.29\times10^{15}$ cycles/s)
- AIEEE - 2012
- Electromagnetic Spectrum
- Which of the plots shown in the figure represents speed (v) of the electron in a hydrogen atom as a function of the principal quantum number (n)?
- The ratio of number of oxygen atoms (O) in 16.0 g ozone $(O_3), \,28.0\, g$ carbon monoxide $(CO)$ and $16.0$ oxygen $(O_2)$ is (Atomic mass: $C = 12,0 = 16$ and Avogadro?? constant $N_A = 6.0 x 10^{23}\, mol^{-1}$)
- AIEEE - 2012
- Mole concept and Molar Masses
View More Questions
Concepts Used:
Group 1 Elements
Group one of alkali metals is s-block elements with just one electron in their s-orbital. They are are alkali metals. They are named so because of the alkaline nature of the hydroxides and oxides.
Alkali metals are characterized by one s-electron in the valence shell of their atoms.
Alkali metals have a corresponding [Noble gas] ns1 electronic configuration. They occupy the first column of the periodic table. Alkali elements are:
- Lithium(Li)
- Sodium(Na)
- Potassium (K)
- Rubidium (Ru)
- Cesium (Cs)
- Francium (Fr)
They have occupied successive periods from first to seven. Francium is a radioactive element with very low half-life.
Electronic Configuration:
- Alkali metals have one electron in their valence shell.
- The electronic configuration is given by ns1. For example, the electronic configuration of lithium is given by 1ns1 2ns1.
- They tend to lose the outer shell electron to form cations with charge +1 (monovalent ions).
This makes them the most electropositive elements and due to the same reason, they are not found in the pure state.