Answer: False
Explanation: The chemical hazard label indicates the class of harzard of chemical products. It appears on their Safety Data Sheet (SDS), which contains a lot of informations about these substances.
The chemical hazard label is divided into four colors and which one has a meaning (categorie) connected with a number, like:
Blue: Health hazard - If the chemical is deadly (4), extreme danger (3), hazardous (2), slightly hazardous (1) or a normal material (0).
Red: Fire hazard (flammability) - If the chemical has flash point bellow 73ºF (4), bellow 100ºF (3), above 100ºF not exceeding 200ºF (2), above 200ºF (1) or will not burn (0).
Yellow: Reactivity (it can be related to instability) - If the chemical may detonate (4), shock and heat may detonete it (3), if it can suffer a violent chemical change (2) or unstable if heated (1) or if it is stable (0).
White: Specific hazard - If the chemical is acid (ACID) or alkali (ALK), for example.
Answer:
Remaining the same
Explanation:
By the Lavoisier's principle the matter can't be created nor destroyed, but always transformed.
It means that in an ecosystem, the matter, and also the energy, is not increasing and not decreasing, the total amount remains the same, but in different forms.
Answer:
Half-reactions:
Cr³⁺ + 1e⁻ → Cr²⁺; Zn → Zn²⁺ + 2e⁻
Net ionic equation:
2Cr³⁺ + Zn → 2Cr²⁺ + Zn²⁺
Explanation:
The Cr³⁺ is reduced to Cr²⁺:
<h3>
Cr³⁺ + 1e⁻ → Cr²⁺ -Half-reaction 1-</h3>
Zn is oxidized to Zn²⁺:
<h3>
Zn → Zn²⁺ + 2e⁻ -Half-reaction 2-</h3>
Twice the reduction of Cr:
2Cr³⁺ + 2e⁻ → 2Cr²⁺
Now this reaction + Oxidation of Zn:
2Cr³⁺ + 2e⁻ + Zn → 2Cr²⁺ + Zn²⁺ + 2e⁻
<h3>2Cr³⁺ + Zn → 2Cr²⁺ + Zn²⁺ - Net ionic equation</h3>
Answer:
The volume of the air is 0.662 L
Explanation:
Charles's Law is a gas law that relates the volume and temperature of a certain amount of gas at constant pressure. This law says that for a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement they have. the gas molecules. This is represented by the quotient that exists between volume and temperature will always have the same value:
If you have a certain volume of gas V1 that is at a temperature T1 at the beginning of the experiment and several the volume of gas to a new value V2, then the temperature will change to T2, and it will be true:
In this case:
- V1= 0.730 L
- T1= 28 °C= 301 °K (0°C= 273°K)
- V2= ?
- T2= 0°C= 273 °K
Replacing:
Solving:
V2=0.662 L
<u><em>The volume of the air is 0.662 L</em></u>