Archives

100 ml of tap water containing ca(hco3)2 was titrated with n/50hcl with methyl orange as indicator. it 30 ml of hcl were required, what is the degree of temporary hardness as ppm.

Milli equivalent of Ca(HCO3)2 = miili equivalent of CaCO3 = mili equivalent of HCl N1V1 = N2V2 1000 × w/(100/2) = 30/50 w= 0.03 g For 100ml... View Article

Reema took 5ml of lead nitrate solution in a beaker and added approximately 4ml of potassium iodide solution to it. what would she observe?

The relation between lead nitrate and potassium iodide is an example of precipitation reaction. Pb (NO3)2 + 2 KI ⟶ ⟶ PbI2 + 2KNO3 (yellow ppt)... View Article

ASSERTION : Reducing character of hydrides of group 16 elements increases as the atomic number of central atom increases. REASON: Due to strong force of attraction of H-E bond

From top to bottom, the size of the elements and their atomic number rise in group 16. The bond energy or force of attraction of the H-E... View Article

In which case is the number of molecules of water maximum?A. 10−3 mol of water.B. 0.00224 L of water vapour at 1 atm and 273 k.C. 0.18 g of water. D. 18 ml of water.

We must first determine the molar mass of water. Water's molecular formula is H2O. 2(molar mass of hydrogen)+molar mass of oxygen Equals... View Article

the freezing point of aqueous solution that contains 5 y mass urea, 1.0 y mass kcl and 10 y mass of glucose is

ΔTf = ΔTf(glucose)+ΔTf(KCl)+ΔTf(urea) But ΔTf = (Kf×W2/M2×W2)×1000 Therefore, [1000×1.86×10/100×180] + [1000×1.86×1×2/74.5×100] +... View Article

nitric acid ( hno3) acts only as an oxidizing agent while nitrous acid(hno2)acts both as an oxidizing as well as reducingagent. explain.

The oxidation number of nitrogen is HNO3 = +5; nevertheless, the maximum oxidation number of nitrogen is +5 and the minimum oxidation number of... View Article

if a solution has 100 times as many hydroxide ions as in pure water at 25ºc, then the ph of the solution at the same temperature will be

Temp = 25oC So, No of hydroxide in pure water is 10−7 A/C to this condition no of hydroxide ion is 2×10−7 So, poH = −log10[2×10−7] 7+0.301=7.301... View Article

if heat of atomisation of ch4(g) is x kj mol–1 then the bond energy of c – h bond (in kj/mol) will be

CH4 → C + 4H, ΔH= + 1665 kJ mol-1, Bond energy of (C – H) bond = 1665/4 = 416.2 kJ mol... View Article

A shopkeeper expects a gain of 22.5% on his cost price. If in a week, his sale was of Rs. 392, what was his profit?

Given, Selling price (SP) = Rs. 392 Profit percent = 22.5% Cost price (CP) = (100/122.5) × Rs. 392 = Rs. 320 So, the profit = SP - CP = Rs. 392 -... View Article

Find the integration of sinx cosx dx.

We know that, sin 2x = 2 sinx cosx So, sinx cosx = (1/2) sin 2x Now, ∫ sinx cosx dx = (1/2) ∫2 sin x cos x dx = (1/2) ∫sin 2x dx = (1/2) (-1/2)... View Article

Find the value of root 53.

The value of root 53 or the square root of 53 is:√53 = 7.28...This can be calculated by the long division method as follows.... View Article

What are the benefits of Vedic maths?

Some of the benefits of Vedic maths are listed below: Calculations become easy and short. We can do simplifications in less time. Students... View Article

What are factorial numbers?

Factorial of numbers can be calculated using the formula:n! = 1 × 2 × 3 × 4 × 5 × ... × (n - 1) × nLet... View Article

What is a perfect square number?

An integer that can be expressed as the square of another integer is called a perfect square. In other words, it is defined as the product of... View Article

Find the area bounded by the inverse of bijective function f(x) = 4x^3 + 6x, the x-axis and the ordinates x = 0 and x = 44.

Given bijective function is: f(x) = 4x3 + 6x f(0) = 4(0)3 + 6(0) = 0 ⇒ f-1(0) = 0 f(2) = 4(2)3 + 6(2) = 32 + 12 = 44 ⇒ f-1(44) = 2 So, the area... View Article