Answer:
- second choice:<em><u> 1.0 g of the solution contains 15 × 10⁻⁶ g of benzene.</u></em>
Explanation:
ppm is a unit of concentration that means parts per million. In grams that is grams of solute per one million (10⁶) grams of solution.
Then, <em>15 ppm of benzene</em> means that there are 15 grams of benzen in 1,000,000 grams of solution.
That leads to:
- 1,000,000 g solution / 15 g benzene
Multiplying numerator and denominator by 10⁻⁶ you find:
- 1,000,000 × 10⁻⁶ g solution / (15 × 10⁻⁶ g benzene)
Simplifying:
- 1.0 g solution / (15 × 10⁻⁶ g benzene)
Which is read as 1.0 g of the solution contains 15 × 10⁻⁶ g of benzene, i.e. the second answer choice.
We are given with
Cobalt phosphate - CoPO4
We are asked for the net ionic equation for the phosphate dissolving in H3O+
The net ionic equation is
CoPO4 (s) + H3O+ (aq) -----> HPO42- (aq) + Co3+ (aq) + H2O *(l)
Answer:
C) ball rollinflown a hill
Explanation:
The question asks to identify the endothermic process in the list of options. By way of elimination, we have;
A) condensation of water on a wind shield of a car
Condensation is an exothermic process. That is, heat is given out as the gases change into the liquid state of matter.
B) formation of copper
This is an exothermic process. Capture of electrons by a cation is always exothermic.
C) ball rollinflown a hill
This is the correct option. Energy is absorbed by the ball as it moves on the hill
D) formation of ice from liquid water
Freezing is an example of exothermic reaction. Heat is given off to the surroundings.
E) oxide from copper and oxygen
Formation of metal oxides and most reactions involving oxygen are exothermic reactions,
When sudden changes occurs in the body. lack of blood flow in the brain
Answer:
120g
Explanation:
Step 1:
We'll begin by writing the balanced equation for the reaction.
Sn + 2HF —> SnF2 + H2
Step 2:
Determination of the number of mole HF needed to react with 3 moles of Sn.
From the balanced equation above,
1 mole of Sn and reacted with 2 moles of HF.
Therefore, 3 moles Sn will react with = 3 x 2 = 6 moles of HF.
Step 3:
Conversion of 6 moles of HF to grams.
Number of mole HF = 6 moles
Molar Mass of HF = 1 + 19 = 20g/mol
Mass of HF =..?
Mass = number of mole x molar Mass
Mass of HF = 6 x 20
Mass of HF = 120g
Therefore, 120g of HF is needed to react with 3 moles of Sn.
