Answer:
6.2 calories
Explanation:
Data Given:
change in temperature = 20 °C
specific heat of gold = 0.031 calories/gram °C
mass of gold = 10.0 grams
Amount of Heat = ?
Solution:
Formula used
Q = Cs.m.ΔT
Where:
Q = amount of heat
Cs = specific heat of gold = 0.031 calories/gram °C
m = mass
ΔT = Change in temperature
Put values in above equation
Q = 0.031 calories/gram °C x 10.0 g x 20 °C
Q = 6.2 calories
So option A is correct = 6.2 calories
Answer:
See explanation
Explanation:
Temperature is defined as a measure of the average kinetic energy of the molecules of a body.
When a substance is heated, the kinetic energy of its molecules increases as the temperature increases; hence the particles of the substance moves faster with increasing temperature.
When heat is withdrawn from a liquid, the temperature decreases and the average kinetic energy of the molecules decreases. The molecules become less energetic hence the liquid changes into solid
A measured value is expressed as a number along with a corresponding unit. The unit represents the dimension of the measured value.
For example:
- Length of an object can be expressed as, value + dimension. for example 10 m where 'm' is the dimension of length; meters
- Volume can be expressed as, value + dimension, for example, 10 L where L is the dimension of volume; Liters.
Ans C) Dimension
Answer:
if i consider this reaction
Fe2O3+ 3CO---》2Fe+ 3CO2
so let's calculate first moles of Fe2O3 i.e. = 256/159.69= 1.6 moles
So the one moles of Fe2O3 is forming three moles of CO2
hence 1.6 moles will form 4.8 moles of CO2
one mole of CO2 is 44 g so 4.8 moles of Co2 is 44×4.8= 211.2 g
so the conclusion is 211.2 g of CO2 can be produced from 256 g Fe2O3!!
i d k it's right or wrong but i tried my best :)
Answer:
b. 54.9%
Explanation:
An emerald gemstone has the formula Be₃Al₂Si₁₆O₁₈. We can find the mass of each element in 1 mole of Be₃Al₂Si₁₆O₁₈ by multiplying the molar mass of the element by its atomicity.
Be: 3 × 9.01 g = 27.03 g
Al: 2 × 26.98 g = 53.96 g
Si: 16 × 28.09 g = 449.4 g
O: 18 × 16.00 g = 288.0 g
Total mass = 818.4 g
The mass percentage of silicon is:
(449.4 g / 818.4 g) × 100% = 54.91%