Answer:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
Explanation: Cause I'm smart like that!
The coefficient of Oxygen in the balanced reaction : 3
<h3>Further explanation</h3>
Given
Reaction(unbalanced)
C2H4+ O2--> CO2+H2O
Required
The coefficient of Oxygen
Solution
C₂H₄+ aO₂⇒ bCO₂+cH₂O
C, left=2, right=b⇒b=2
H, left=4, right=2c⇒2c=4⇒c=2
O, left=2a, right=2b+c⇒2a=2b+c⇒2a=2.2+2⇒2a=6⇒a=3
The equation becomes :
<em>C₂H₄+ 3O₂⇒ 2CO₂+2H₂O</em>
Answer:
The correct answer is "A buffer resists pH change by neutralizing added acids and bases".
Explanation:
In chemistry, a buffer is defined as an aquoeous solution that resist pH changes. Buffers are comprised of a weak acid (HA) and its conjugate base (A−) in an equilibrium relation, which results in the buffer neutralizing added acids and bases. Buffers play a crucial role in living beings since they provide a relative stable environment for the cells in what is known as homeostasis.
(i) We start by calculating the mass of sugar in the solution:
mass of sugar = concentration × solution mass
mass of sugar = 2.5/100 × 500 = 12.5 g
Then now we can calculate the amount of water:
solution mass = mass of sugar + mass of water
mass of water = solution mass - mass of sugar
mass of water = 500 - 12.5 = 487.5 g
(ii) We use the following reasoning:
If 500 g solution contains 12.5 g sugar
Then X g solution contains 75 g sugar
X=(500×75)/12.5 = 3000 g solution
Now to get the amount of solution in liters we use density (we assume that is equal to 1):
Density = mass / volume
Volume = mass / density
Volume = 3000 / 1 = 3000 liters of sugar solution
Answer:
240 seconds
Explanation:
Data Given:
Distance Radio travel to earth = 7.19 ×10⁷ km
Speed of this radio signal = 3.00 ×10⁸ m/s
Solution:
First convert Km to m
1 km = 1000 m
7.19 ×10⁷ km = 7.19 ×10⁷ x 1000 = 7.19 × 10¹⁰m
Formula used to calculate time
Speed (S) = distance (d) / time (t)
rearrange above equation for time
time (t) = distance (d) / Speed (S) . . . . . . . . .(1)
Put values in equation 1
time (t) = 7.19 × 10¹⁰/ 3.00 ×10⁸ m/s
time (t) = 240 s
So 240 seconds it take for the signal to reach the earth
