So,
With addition, we the last digit we keep will be the one which is known for both individual values.
We know 2.13 to the hundredths, but we only know 1 to the ones. Therefore, we will round off in the ones place.
2.13 + 1 = 3.13 (unrounded)
= 3 (rounded)
Hope this helps!
Answer:
<em><u>Glass that will sink</u></em>
- alkali zinc borosilicate with a density of 2.57 g/mL in a solution with a density of 2.46 g/mL
- potash soda lead with a density of 3.05 g/mL in a solution with a density of 1.65 g/mL
<em><u>Glass that will float</u></em>
- soda borosilicate with a density of 2.27 g/mL in a solution with a density of 2.62 g/mL
- alkali strontium with a density of 2.26 g/mL in a solution with a density of 2.34 g/mL
<em><u>Glass that will not sink or float</u></em>
- potash borosilicate with a density of 2.16 g/mL in a solution with a density of 2.16 g/mL
Explanation:
Density is the property of matter that states the ratio of the amount of matter, its mass, to the space occupied by it, its volume.
So, the mathematical expression for the density is:
By comparing the density of a material with the density of a liquid, you will be able to determine whether object will float, sink, or do neither when immersed in the liquid.
The greater the density of an object the more it will try to sink in the liquid.
As you must have experienced many times an inflatable ball (whose density is very low) will float in water, but a stone (whose denisty is greater) will sink in water.
The flotation condition may be summarized by:
- When the density of the object < density of the liquid, the object will float
- When the density of the object = density of the liquid: the object will neither float nor sink
- When the density of the object > density of the liquid: the object will sink.
<em><u>Glass that will sink</u></em>
- alkali zinc borosilicate with a density of 2.57 g/mL in a solution with a density of 2.46 g/mL, because 2.57 > 2.46.
- potash soda lead with a density of 3.05 g/mL in a solution with a density of 1.65 g/mL, because 3.05 > 1.65.
<u><em>Glass that will float</em></u>
- soda borosilicate with a density of 2.27 g/mL in a solution with a density of 2.62 g/mL, because 2.27 < 2.62.
- alkali strontium with a density of 2.26 g/mL in a solution with a density of 2.34 g/mL, because 2.26 < 2.34.
<em><u>Glass that will not sink or float</u></em>
- potash borosilicate with a density of 2.16 g/mL in a solution with a density of 2.16 g/mL, because 2.16 = 2.16
Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
Missing in your question :
Ksp of(CaCO3)= 4.5 x 10 -9
Ka1 for (H2CO3) = 4.7 x 10^-7
Ka2 for (H2CO3) = 5.6 x 10 ^-11
1) equation 1 for Ksp = 4.5 x 10^-9
CaCO3(s)→ Ca +2(aq) + CO3-2(aq)
2) equation 2 for Ka1 = 4.7 x 10^-7
H2CO3 + H2O → HCO3- + H3O+
3) equation 3 for Ka2 = 5.6 x 10^-11
HCO3-(aq) + H2O(l) → CO3-2 (aq) + H3O+(aq)
so, form equation 1& 2&3 we can get the overall equation:
CaCO3(s) + H+(aq) → Ca2+(aq) + HCO3-(aq)
note: you could get the overall equation by adding equation 1 to the inverse of equation 3 as the following:
when the inverse of equation 3 is :
CO3-2 (aq) + H3O+ (aq) ↔ HCO3- (aq) + H2O(l) Ka2^-1 = 1.79 x 10^10
when we add it to equation 1
CaCO3(s) ↔ Ca2+(aq) + CO3-2(aq) Ksp = 4.5 x 10^-9
∴ the overall equation will be as we have mentioned before:
when H3O+ = H+
CaCO3(s) + H+(aq) ↔ Ca2+ (aq) + HCO3-(aq) K= 80.55
from the overall equation:
∴K = [Ca2+][HCO3-] / [H+]
when we have [Ca2+] = [HCO3-] so we can assume both = X
∴K = X^2 / [H+]
when we have the PH = 5.6 so we can get [H+]
PH = - ㏒[H+]
5.6 = -㏒[H]
∴[H] = 2.5 x 10^-6
so, by substitution on K expression:
∴ 80.55 = X^2 / (2.5 x10^-6)
∴X = 0.0142
∴[Ca2+] = X = 0.0142
Extensive property is that which depends on the amount of matter in a sample. For example: mass, volume, size are all extensive properties
Intensive properties are independent of the amount of matter. These include; boiling point, melting point, color and so on.
In the given examples:
Both sample A and B have the same volume (1000 ml) i.e. the same extensive property. However, they have different freezing points i.e. different intensive property.
Ans: D) The two substances are not the same because their intensive property is different.
