When you graph an inequality you used a closed dot or a open dot

1 answer:

4 0

For ≤ and ≥ , use a closed dot to indicate the number itself is part of the solution. For < and >, use an open circle to indicate the number itself is not part of the solution.

You might be interested in

Americans spend up to $100 billion annually for bottled water (41 billion gallons). The only beverages with higher sales are car

grigory [225]

Answer: C) be hypertonic to Tank B.

Explanation:

The ability of an extracellular solution to move water in or out of a cell by osmosis is known as its tonicity. Additionally, the tonicity of a solution is related to its osmolarity, which is the total concentration of all the solutes in the solution.

Three terms (hypothonic, isotonic and hypertonic) are used to compare the osmolarity of a solution with respect to the osmolarity of the liquid that is found after the membrane. When we use these terms, we only take into account solutes that can not cross the membrane, which in this case are minerals.

If the liquid in tank A has a lower osmolarity (lower concentration of solute) than the liquid in tank B, the liquid in tank A would be hypotonic with respect to the latter.
If the liquid in tank A has a greater osmolarity (higher concentration of solute) than the liquid in tank B, the liquid in tank A would be hypertonic with respect to the latter.
If the liquid in tank A has the same osmolarity (equal concentration of solute) as the liquid in tank B, the liquid in tank A would be isotonic with respect to the latter.

In the case of the problem, option A is impossible because the minerals can not cross the membrane, since it is permeable to water only. There is no way that the concentration of minerals decreases in tank A, so the solution in this tank can not be hypotonic with respect to the one in Tank B.

Equally, both solutions can not be isotonic and neither we can say that the solution in tank A has more minerals that the one in tank B because the liquid present in tank B is purified water that should not have minerals. Therefore, options B and D are also not correct.

Finally, the correct option is C, since in the purification procedure the water is extracted from the solution in tank A to obtain a greater quantity of purified water in tank B. In this way, the solution in Tank A would be hypertonic to Tank B.

5 0

3 years ago

Hard water often contains dissolved Ca2+ and Mg2+ ions. One way to soften water is to add phosphates. The phosphate ion forms in

avanturin [10]

5.5×10−2M in calcium chloride and 8.0×10−2M in magnesium nitrate.
What mass of sodium phosphate must be added to 1.5L of this solution to completely eliminate the hard water ion

1) Content of Ca (2+) ions

Calcium chloride = CaCl2

Ionization equation: CaCl2 ---> Ca (2+) + 2 Cl (-)

=> Molar ratios: 1 mol of CaCl2 : 1 mol Ca(2+) : 2 mol Cl(-)

Calculate the number of moles of CaCl2 in 1.5 liters of 5.5 * 10^-2 M solution

M = n / V => n = M*V = 5.5 * 10^ -2 M * 1.5 l = 0.0825 mol CaCl2

=> 0.0825 mol Ca(2+)

2) Number of phosphate ions needed to react with 0.0825 mol Ca(2+)

formula of phospahte ion: PO4 (3-)

molar ratio: 2PO4(3-) + 3Ca(2+) = Ca3 (PO4)2

Proportion: 2 mol PO4(3-) / 3 mol Ca(2+) = x / 0.0825 mol Ca(2+)

=> x = 0.0825 coml Ca(2+) * 2 mol PO4(3-) / 3 mol Ca(2+) = 0.055 mol PO4(3-)

3) Content of Mg(2+) ions

Ionization equation: Mg (NO3)2 ----> Mg(2+) + 2 NO3 (-)

Molar ratios: 1 mol Mg(NO3)2 : 1 mol Mg(2+) + 2 mol NO3(-)

number of moles of Mg(NO3)2 in 1.5 liter of 8.0 * 10^-2 M solution

n = M * V = 8.0 * 10^ -2 M * 1.5 liter = 0.12 moles Mg(NO3)2

ions of Mg(2+) = 0.12 mol Mg(NO3)2 * 1 mol Mg(2+) / mol Mg(NO3)2 = 0.12 mol Mg(2+)

4) Number of phosphate ions needed to react with 0.12 mol Mg(2+)

2PO4(3-) + 3Mg(2+) = Mg3(PO4)2

=> 2 mol PO4(3-) / 3 mol Mg(2+) = x / 0.12 mol Mg(2+)

=> x = 0.12 * 2/3 mol PO4(3-) = 0.16 mol PO4(3-)

5) Total number of moles of PO4(3-)

0.055 mol + 0.16 mol = 0.215 mol

6) Sodium phosphate

Sodium phosphate = Na3(PO4)

Na3PO4 ---> 3Na(+) + PO4(3-)

=> 1 mol Na3PO4 : 1 mol PO4(3-)

=> 0.215 mol PO4(3-) : 0.215 mol Na3PO4

mass in grams = number of moles * molar mass

molar mass of Na3 PO4 = 3*23 g/mol + 31 g/mol + 4*16 g/mol = 164 g/mol

=> mass in grams = 0.215 mol * 164 g/mol = 35.26 g

Answer: 35.26 g of sodium phosphate

5 0

3 years ago

The descriptions below explain two ways that water is used by plants on a sunny day. I. In a process called transpiration, some

eduard

The correct answer for this question is this one: "In transpiration, because some of its properties change, water undergoes a physical change but keeps its identity. In photosynthesis, because its identity changes, water undergoes a chemical change. "
Hope this helps answer your question and have a nice day ahead.

8 0

3 years ago

Read 2 more answers

What would happen to the position of the equilibrium when the following changes are made to the reaction below?

love history [14]

Answer:

I don't know good luck

Explanation:

6 0

3 years ago

Read 2 more answers

Which atomic model was proposed as a result of J.J Thomsons work?