Answer:
A. Kilo , K, multiplication by 1000
B. Centi, c
C. Deci, d
D. Mili, m
E. Mega, M
F. Micro, u
When a substance is changing state, its temperature remains constant. This is because energy is used to increase/decrease kinetic energy of the molecules of the substance, increasing/decreasing the inter-molecular distance and overcoming the energy bonds present between the molecules. Therefore, no energy is used to raise the temperature of the substance and therefore it remains constant
Answer:
40.4 kJ
Explanation:
Step 1: Given data
- Heat of sublimation of CO₂ (ΔH°sub): 32.3 kJ/mol
Step 2: Calculate the moles corresponding to 55.0 g of CO₂
The molar mass of CO₂ is 44.01 g/mol.
n = 55.0 g × 1 mol/44.01 g = 1.25 mol
Step 3: Calculate the heat (Q) required to sublimate 1.25 moles of CO₂
We will use the following expression.
Q = n × ΔH°sub
Q = 1.25 mol × 32.3 kJ/mol = 40.4 kJ
Molar mass of :
O2 = 16 * 2 = 32 g/mol
CO2 = 12 + 16 * 2 = 44 g/mol
<span>Balanced chemical equation :
</span>
1 CH4 +
2 O2 =
1 CO2 +
2 H2O
↓ ↓
2 moles 1 mole
2* 32 g O2 ----------> 1* 44 g CO2
x g O2 ------------> 10.0 g CO2
44 x = 2 * 32*10.0
44 x = 640
of O2
If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.
