Oxygen is a reactant in combustion and the concentration of oxygen is higher in pure oxygenthan it is in air.
Explanation:
A property that does not bring any change in chemical composition of a substance are known as physical properties.
For example, shape, size, mass, volume, density, hardness etc of a substance are all physical properties.
On the other hand, a property that changes chemical composition of a substance is known as chemical property.
For example, precipitation, reactivity, toxicity etc are chemical property.
Therefore, given descriptions are separated according to their physical and chemical properties as follows.
Physical properties:
- Zinc has a hardness on the Mohs scale of 2.5 and a density of 7.13 g/cm3 at .
- Zinc melts at .
Chemical properties:
- When zinc granules are added to dilute sulfuric acid, hydrogen is given off and the metal dissolves.
- It reacts slowly with oxygen gas at elevated temperatures to form zinc oxide, ZnO.
Answer:
d. 54.9 kPa
Explanation:
mmHg and Pa are units of pressure used in chemistry principally in the study of gases. 1mmHg is equal to 133.322Pa. 412mmHg are:
412 mmHg * (133.322Pa / 1mmHg) = 54929 Pa
The prefix K (Kilo) represents one thousand of the determined unit.
54929Pa are:
54929Pa * (1KPa / 1000Pa) = 54.9kPa
Right answer is:
<h3>d. 54.9 kPa
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Answer:
You can increase your precision in the lab by paying close attention to detail, using equipment properly and increasing your sample size. Ensure that your equipment is properly calibrated, functioning, clean and ready to use.