Answer:
Overall, ethanol is considered to be better for the environment than petrol. Ethanol-fuelled vehicles produce lower carbon dioxide emissions, and the same or lower levels of hydrocarbon and oxides of nitrogen emissions.
Explanation:
Answer: Metals bond with metals.
Explanation: A metallic bond is a sharing of electrons between many atoms of a metal element. Metallic bonding is when positive ions (metals) are in a 'sea of negative electrons'. The electrons are delocalised, which means they can move around easily and carry charge, and this enables it to conduct electricity, even in a solid state. The big pool of electrons is like a free-for-all in that any valence electron can move to any atom within the material.
Scale and measuring tape.
To determine the mass and volume, you can find the density. The block will float if its density is less than that of water.
2.469 could be maid dont forget to hit that thanks button
Answer:
6.4 × 10^-10 M
Explanation:
The molar solubility of the ions in a compound can be calculated from the Ksp (solubility constant).
CaF2 will dissociate as follows:
CaF2 ⇌Ca2+ + 2F-
1 mole of Calcium ion (x)
2 moles of fluorine ion (2x)
NaF will also dissociate as follows:
NaF ⇌ Na+ + F-
Where Na+ = 0.25M
F- = 0.25M
The total concentration of fluoride ion in the solution is (2x + 0.25M), however, due to common ion effect i.e. 2x<0.25, 2x can be neglected. This means that concentration of fluoride ion will be 0.25M
Ksp = {Ca2+}{F-}^2
Ksp = {x}{0.25}^2
4.0 × 10^-11 = 0.25^2 × x
4.0 × 10^-11 = 0.0625x
x = 4.0 × 10^-11 ÷ 6.25 × 10^-2
x = 4/6.25 × 10^ (-11+2)
x = 0.64 × 10^-9
x = 6.4 × 10^-10
Therefore, the molar solubility of CaF2 in NaF solution is 6.4 × 10^-10M
