Qual das alternativas a seguir é uma mistura homogênea?
Escolha uma:a. Mercúrio metálico e água. b. Gelo e água líquida. c. Areia e carvão em pó. d. Nitrogênio gasoso e vapor d’água. e. Poeira e ar atmosférico.
Answer:
Explanation:
1. Miles travelled in an average month

2. Using a gasoline powered vehicle
(a) Moles of heptane used
(b) Equation for combustion
C₇H₁₆ + O₂ ⟶ 7CO₂ + 8H₂O
(c) Moles of CO₂ formed
(d) Volume of CO₂ formed
At 20 °C and 1 atm, the molar volume of a gas is 24.0 L.
3. Using an electric vehicle
(a) Theoretical energy used

(b) Actual energy used
The power station is only 85 % efficient.

(c) Combustion of CH₄
CH₄ + 2O₂ ⟶ CO₂ +2 H₂O
(d) Equivalent volume of CO₂
The heat of combustion of methane is -802.3 kJ·mol⁻¹

4. Comparison

We are asked to convert 25 cg to units of hg.
1 cg = 1 centigram = 10⁻² g
1 hg = 1 hectogram = 10² g
The options given are:
a) 1 hg/ 10² g
b) 10² cg/ 1 hg
c) 10² hg/ 1 cg
d) 10⁻² g/ 1 cg
To convert 25 cg to 1 hg, we could convert the 25 cg to grams first, then grams to hg.
25 cg · 10⁻² g/ 1cg = 0.25 g
Here we have converted our number from cg to grams. We can use another conversion of grams to hg to complete the conversion.
0.25 g · 1 hg/ 10² g = 0.0025 hg
Therefore, the first conversion we used was d) 10⁻² g/ 1 cg.
Answer:
Explanation:
Electrons are transferred from atoms of sodium to atoms of phosophorus. This transfer makes the sodium atoms positive and the phosphorus atoms negative. As a result, the sodium and phosphorus atoms strongly attract each other.
Deposition. Particles settle to the bottom of still water after being eroded.