Answer:
Sample A is a mixture
Sample B is a mixture
Explanation:
For sample A, we are told that the originally yellow solid was dissolved and we obtained an orange powder at the bottom of the beaker. Subsequently, only about 30.0 g of solid was recovered out of the 50.0g of solid dissolved. This implies that the solid is not pure and must be a mixture. The other components of the mixture must have remained in solution accounting for the loss in mass of solid obtained.
For sample B, we are told that boiling started at 66.2°C and continued until 76.0°C. The implication of this is that B must be a mixture since it boils over a range of temperatures. Pure substances have a sharp boiling point.
Answer:
2
Explanation:
1. The dew is formed when the water vapor at the atmosphere contacts the leaves, which are at a low temperature, so, the vapor temperature decreases, and the liquid is formed. So, it's a gas to liquid change.
2. Ice cubes are at the solid-state, thus this transformation is solid to a liquid change.
3. The cold juice is at a low temperature, so when the water vapor of the air contacts with the glass, its temperature decreases, and its change to a liquid phase. So, it's a gas to liquid change.
4. The evaporated water from the Earth's surface goes to the atmosphere, and, at high altitudes, the temperature is low, so the water vapor condenses and the drops get closer together forming the clouds. So, it's a gas to a liquid change.
I think thee correct answer from the choices listed above is option D. <span>When a physical change in a sample occurs, composition of the sample does not change. It stays the same. Also, the properties of the sample will still be the same. Hope this answers the question.</span>
The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation of an atom in a chemical compound.
<u>Explanation:</u>
The oxidation number of an atom is the charge that atom would have if the compound was composed of ions. 1. The oxidation number of an atom is zero in a neutral substance that contains atoms of only one element. The oxidation number of simple ions is equal to the charge on the ion.
The oxidation number of a mono atomic ion equals the charge of the ion. The oxidation number of H is +1, but it is -1 in when combined with less electro negative elements. The oxidation number of O in compounds is usually -2, but it is -1 in peroxides. The oxidation number of a Group 1 element in a compound is +1.
Answer:
63.6 dm³
Explanation:
Volume of gas= no. of moles ×24dm³
Thus, volume of N₂O
= 2.65 × 24
= 63.6 dm³
