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harina [27]
2 years ago
11

I Need Help on these science questions

Chemistry
2 answers:
gtnhenbr [62]2 years ago
5 0

Answer:

Page 1:  Embryonic stem cells | Page 2: I don't know | Page 3: Amoeba. Amoeba is a unicellular organism that has the ability to alter its shape. (I believe)

Explanation:

aalyn [17]2 years ago
4 0
Page 1:A,composed of one cell
Page 2:A,A and B
Page 3:cells reproduce through photosynthesis
You might be interested in
A chemist dissolves 867. mg of pure barium hydroxide in enough water to make up 170. mL of solution. Calculate the pH of the sol
Ilya [14]

Answer: The pH of the solution is 11.2

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

Molarity=\frac{n\times 1000}{V_s}

where,

n = moles of solute

V_s = volume of solution in ml

moles of Ba(OH)_2 = \frac{\text {given mass}}{\text {Molar mass}}=\frac{0.867g}{171g/mol}=0.00507mol         (1g=1000mg)

Now put all the given values in the formula of molality, we get

Molarity=\frac{0.00507\times 1000}{170}

Molarity=0.0298

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

pOH=-\log [OH^-]

Ba(OH)_2\rightarrow Ba^{2+}+2OH^{-}

According to stoichiometry,

1 mole of Ba(OH)_2 gives 2 mole of OH^-

Thus 0.0298 moles of Ba(OH)_2 gives =\frac{2}{1}\times 0.0298=0.0596 moles of OH^-

Putting in the values:

pOH=-\log[0.0596]=2.82

pH+pOH=14

pH=14-2.82

pH=11.2

Thus the pH of the solution is 11.2

8 0
3 years ago
Calculate the heat absorbed by a sample of water that has a mass of 45.00 g when the temperature increases from 21.0oC to 38.5 o
Elenna [48]

Answer:

The heat absorbed by the sample of water is 3,294.9 J

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

The sensible heat of a body is the amount of heat received or transferred by a body when it undergoes a temperature variation (Δt) without there being a change of physical state (solid, liquid or gaseous). Its mathematical expression is:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case:

  • Q=?
  • m= 45 g
  • c= 4.184 \frac{J}{g*C}
  • ΔT= Tfinal - Tinitial= 38.5 C - 21 C= 17.5 C

Replacing:

Q= 4.184 \frac{J}{g*C} * 45 g* 17.5 C

Solving:

Q=3,294.9 J

<u><em>The heat absorbed by the sample of water is 3,294.9 J</em></u>

<u><em></em></u>

8 0
3 years ago
Stuck on question 22
Klio2033 [76]
The answer is c. because you have to increase concentration of h2
7 0
3 years ago
Are scientific theories all proven facts?
SSSSS [86.1K]
No! That’s why they’re called theories. Most of them have a lot of facts to back it up however the theories themselves are either proven or just hypothetical.
8 0
2 years ago
Read 2 more answers
Is Orange Juice with Pulp is Heterogeneous<br> or Homogeneous Mixture?
nalin [4]

Answer:

I think so henterogeneous

8 0
3 years ago
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