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rusak2 [61]
3 years ago
14

NEED HELP QUICK!!! pls give quick reason why

Chemistry
1 answer:
weqwewe [10]3 years ago
4 0

Answer:

- 20 J

Explanation:

Heat of Reaction = Heat of Products - Heat of Reactants

From the graph;

Heat of Products = 10

Heat of Reactants = 30

Heat of Reaction = 10 - 30 = -20 J

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15. transition metals has ____ valence electrons
Gemiola [76]

2 valence electrons

Explanation:

Most transition metals have 2 valence electrons. Valence electrons are the sum total of all the electrons in the highest energy level (principal quantum number n). Most transition metals have an electron configuration that is ns2(n−1)d , so those ns2 electrons are the valence electrons.

8 0
3 years ago
The directional term that refers to an area or structure off to the side and away from the midline is __________.
Gnesinka [82]

Answer:

Lateral

Explanation:

Is the opposite side of the midline

8 0
3 years ago
What are all the elements to the left of the zigzag line in a periodic table called?
Kitty [74]
They are called metals
4 0
3 years ago
A 256 mL sample of HCl gas is in a flask where it exerts a force (pressure) of 67.5 mmHg. What is the pressure of the gas if it
Effectus [21]

Answer:

The pressure in the new flask would be 128\; \rm mmHg if the \rm HCl here acts like an ideal gas.  

Explanation:

Assume that the \rm HCl sample here acts like an ideal gas. By Boyle's Law, the pressure P of the gas should be inversely proportional to its volume V.

For example, let the initial volume and pressure of the sample be V_1 and P_1. The new volume V_2 and pressure P_2 of this sample shall satisfy the equation: P_1 \cdot V_1 =P_2 \cdot V_2.

In this question,

  • The initial volume of the gas is V_1= 256\; \rm mL.
  • The initial pressure of the gas is P_1 = 67.5\; \rm mmHg.
  • The new volume of the gas is V_2 = 135\; \rm mL.

The goal is to find the new pressure of this gas, P_2.

Assume that this sample is indeed an ideal gas. Then the equation P_1 \cdot V_1 =P_2 \cdot V_2 should still hold. Rearrange the equation to separate the unknown, P_2. Note: make sure that the units for V_1 and V_2 are the same before evaluating. That way, the unit of

\begin{aligned} & P_2\\ &= \frac{P_1 \cdot V_1}{V_2} \\ &= \frac{256\; \rm mL \times 67.5\; \rm mmHg}{135\; \rm mL} \\ & \approx 128\; \rm mmHg\end{aligned}.

3 0
3 years ago
how many calories is in one peanut if the volume of water is 10 mL and the water temperature is rise 4 degrees celsius
liraira [26]

Answer:

40.02 calories

Explanation:

V = 10 mL = 10g

we know t went <em>up</em> by 4°C, this is our ∆t as it is a change.

Formula that ties it together: Q = mc∆t

where,

Q = energy absorbed by water

m = mass of water

c = specific heat of water (constant)

∆t = temperature change

Q = (10 g) x (4.186 J/g•°C) x (4°C)

Q = 167.44 J

Joules to Calories:

167.44 J x 1 cal/4.184 J = 40.02 calories

(makes sense as in image it is close to the value).

4 0
3 years ago
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