What is the function of an arrow ( -7) and a plus sign ( ) in a chemical equation?

1 answer:

3 0

The plus sign is to show that something is added

the arrow is to show the products, which are the things you get at the end

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Question 21 (2 points)

m_a_m_a [10]

Answer:

i would say sensory memory, aka muscle memory.

Explanation:

8 0

2 years ago

Read 2 more answers

Calculate the specific heat capacity for a 22.7-g sample of lead that absorbs 237 J when its temperature increases from 29.8 °C

soldier1979 [14.2K]

Answer:

$\boxed {\boxed {\sf c\approx 0.159 \ J/ g \textdegree C}}$

Explanation:

We are asked to find the specific heat capacity of a sample of lead. The formula for calculating the specific heat capacity is:

$c= \frac{Q}{m \times \Delta T}$

The heat absorbed (Q) is 237 Joules. The mass of the lead sample (m) is 22.7 grams. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature. The temperature increases <em>from</em> 29.8 °C <em>to </em>95.6 °C.

ΔT = final temperature -inital temperature
ΔT= 95.6 °C - 29.8 °C = 65.8 °C

Now we know all three variables and can substitute them into the formula.

Q= 237 J
m= 22.7 g
ΔT = 65.8 °C

$c= \frac {237 \ J}{22.7 \ g \ \times \ 65.8 \textdegree C}$

Solve the denominator.

22.7 g * 65.8 °C = 1493.66 g °C

$c= \frac {237 \ J}{1493.66 \ g \textdegree C}$

Divide.

$c= 0.1586706479 J /g \textdegree C$

The original values of heat, temperature, and mass all have 3 significant figures, so our answer must have the same. For the number we found that is the thousandth place. The 6 in the ten-thousandth place tells us to round the 8 up to a 9.

$c \approx 0.159 \ J/g \textdegree C$

The specific heat capacity of lead is approximately <u>0.159 Joules per gram degree Celsius.</u>

3 0

1 year ago

Using only the following elements P, Br, and Mg, give the formulas for:A. an ionic compound. B. a molecular compound with polar

Talja [164]

Answer:

<h2>1. Ionic compound- $MgBr_2$ </h2><h2>2. Polar molecular compound- $PBr_3$ </h2>

Explanation:

Mg is a metal that has 12 atomic numbers and thus its electronic configuration is $1s^22s^22p^63s^2$ . The outer most shell of this element has 2 electrons so it loses 2 electrons and thus form $Mg^2^+$ ions. Br is a nonmetal and has 35 atomic number so its electronic configuration is $1s^22s^22p^63s^23p^64s^23d^1^04p^5$ . Since its outermost shell has 7 electrons so it can accept one electron and thus forms $Br^-$ . So magnesium ion and bromide ion combine and forms an ionic compound $MgBr_2$ .