Ask question

Ask question

All categories

3 years ago

8

The temperature of a sample of iron with a mass of 10.0 g changed from 50.4°C to 25.0°C with the release of 47 calories of heat.

What type of reaction id occurring?

1 answer:

sleet_krkn [62]3 years ago

6 0

This would be concidered a chemical reaction.

You might be interested in

How many grams of the excess reactant are left over according to the reaction below given that you start with 10.0 g of Al and 1

valentinak56 [21]

<span>4 Al + 3 O2 → 2 Al2O3

(10.0 g Al) / (26.98154 g Al/mol) = 0.37062 mol Al
(19.0 g O2) / (31.99886 g O2/mol) = 0.59377 mol O2

0.37062 mole of Al would react completely with 0.37062 x (3/4) = 0.277965 mole of O2, but there is more O2 present than that, so O2 is in excess.

((0.59377 mol O2 initially) - (0.277965 mol O2 reacted)) x (31.99886 g O2/mol) =
10.1 g O2 left over</span><span>
</span>

7 0

3 years ago

Read 2 more answers

A fossil was analyzed and determined to have a carbon-14 level that is 70 % that of living organisms. The half-life of C-14 is 5

Citrus2011 [14]

Answer: 2948

Explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{5730}=1.21\times 10^{-4}years^{-1}$

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $1.21\times 10^{-4}years^{-1}$

t = age of sample = ?

a = let initial amount of the reactant = 100

a - x = amount left after decay process = $\frac{70}{100}\times 100=70$

$t=\frac{2.303}{1.21\times 10^{-4}}\log\frac{100}{70}$

$t=2948years$

Thus the fossil is 2948 years old.

5 0

3 years ago

A student observes that a patch of grass in a garden can reproduce without seed formation by using the structures that grow hori

liraira [26]

RUNNERS , well that what i would pick

3 0

3 years ago

Please help me with this honestly I'm clueless It's 7th science work......please help

olganol [36]

Hiii
3. describe the physical characters that can be observed: phenotype

6. a specific characteristic of an organism: trait

7. a section of DNA that provides instructions for specific traits: genes

8. allele expressed in the phenotype even if only one copy is present in the genotype: dominant

hope this helped :)

6 0

3 years ago

Read 2 more answers

Inside a room, the air is often warmer near the ceiling then near the floor. Which of the following accounts for this difference

Vanyuwa [196]

The correct answer is C. convection

4 0

3 years ago