Thermal Properties of Matter

By definition, one calorie is the amount of heat energy required to raise the temperature of one gram of liquid water by one degree Celsius. In the SI system, this is approximately 4.184 Joules.

On the Fahrenheit scale, the freezing point of pure water at standard atmospheric pressure is exactly 32 °F. 0 °F is the freezing point of a specific brine solution, and 47 °F and 19 °F are unrelated temperatures.

Under normal atmospheric pressure (1 atm), pure water freezes at 0 degrees Celsius (32 degrees Fahrenheit). This is the standard freezing point used in most scientific and everyday contexts. -72°C and -100°C are extremely cold, while 100°C is actually the boiling point of water.

Increased pressure inside a pressure cooker raises the boiling point of water above 100°C. At standard atmospheric pressure, water boils at 100°C, but higher pressure requires higher temperature for boiling.

The conversion formula is F = (C × 9/5) + 32. For 100°C: (100 × 9/5) + 32 = 180 + 32 = 212°F. Option C is the Kelvin equivalent (373K), and options A and D are incorrect conversions.

At standard atmospheric pressure, water freezes at 0°C. Option A -0 is not standard notation (zero is neither positive nor negative), and +100°C is the boiling point.

Water boils at 373 Kelvin (100°C) at standard atmospheric pressure. The Kelvin scale starts at absolute zero (0K = -273°C), so room temperature is about 300K. 273K is the freezing point of water (0°C), and 173K would be -100°C, far below freezing.

Water freezes at 0 degrees Celsius (32 degrees Fahrenheit) under standard atmospheric pressure at sea level. This is the freezing point of water - the temperature at which liquid water transitions to solid ice. The other options include absolute zero (-273°C), an incorrect negative value, and water's boiling point (100°C).

By definition, 1 calorie (small 'c') is the amount of heat energy required to raise the temperature of 1 gram of water by 1°C. This is different from a Calorie (capital 'C'), which equals 1000 calories and is used in nutrition.

 Z = -98 ⁰ {Z – (- 14)}/{65 – (- 14)} = (F - 32)/180 (- 98 +14)/(65 + 14) = (F - 32)/180 - 84/79 = (F - 32)/180 (- 84/79) x 180 = (F- 32) - 191 + 32 = F F =  - 159⁰F

 Let mass of hot water be m kg. Mass of cold water = (20 - m)kg Heat taken by cold water               = (20 - m) x 1 x (35 – 10) Heat given by hot water              = m x 1 x (100 – 35) Law of mixture gives Heat given by hot water = Heat taken by cold water m x 1 x (100 – 35) = (20 - m) x 1 x (35 – 10) 65 m = (20 - m) x 25 65 m = 500 – 25 m 90 m = 500      m = 500/90         = 5.56 kg

Let final temperature be θ. Heat taken by ice = m₁L + m₁c₁∆θ₁                 = 5 x 80 + 5 x 1(θ-0)                 = 400 + 5θ Heat given by water at 40⁰ C                 = m₂c₂∆θ₂                 = 20 x 1 x (40-θ)                 = 800 -20θ Heat given = Heat taken 800 -20θ   =  400+ 5θ 800-400   =   5θ + 20θ        400      = 25θ               θ     = 400/25                      = 16⁰ C

Water has a unique density anomaly - it reaches maximum density at approximately 4°C. Above and below this temperature, water becomes less dense due to changes in molecular arrangement and hydrogen bonding. This property is crucial for aquatic life.

This is the right answer. 70% of earth's surface is covered with water. Boiling point of water is 100 degree Celsius. Freezing point of water is 0 degree Celsius and only 1 % of water is readily available for human use.

Water has the highest specific heat capacity among all common substances (~4.18 J/g°C). This means water can absorb more heat energy per unit mass for a given temperature change compared to metals, wood, soil, or other materials.