Answer: conversion of ice to steam
Explanation: Endothermic process is one in which energy is absorbed by the system.
Conversion of ice to steam is change of solid phase to gaseous phase, thus energy is required to break the strong inter molecular forces of attraction in solids to convert it into gaseous phase.
Conversion of steam to ice, conversion of steam to water and conversion of water to ice releases energy and are examples of exothermic processes.
Explanation:
Charles' law gives the relationship between the volume and the temperature of the gas. Mathematically,
Volume ∝ Temperature
i.e. 
We have, V₁ = 1.6 L, T₁ = 278 K, T₂ = 253, V₂=?
So, the new volume is 1.45 L.
Answer:
pH = 3.49
Explanation:
We have a buffer system formed by a weak acid (HNO₂) and its conjugate base (NO₂⁻ coming from KNO₂). We can calculate the pH of a buffer ssytem using the Henderson-Hasselbach equation.
pH = pKa + log [base] / [acid]
pH = -log Ka + log [NO₂⁻] / [HNO₂]
pH = -log 4.50 × 10⁻⁴ + log 0.290 M / 0.210 M
pH = 3.49
Answer:
<h3>A . Alkali metals</h3>
Explanation:
The highlighted elements of the periodic table belong to the alkali metal element family. The alkali metals are recognized as a group and family of elements. These elements are metals. Sodium and potassium are examples of elements in this family.
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